Valid Passport + 3 Months

Just wanted to make sure everyone saw on the Festival's General Info page that your passport needs to be "valid for at least 3 months after the end of your stay."

If you're from the U.S. or an EU country, you don't need a visa for Portugal, per this link about Entry Formalities on VisitPortugal from that page.

Prices in Cascais

Thanks to DavidB for this link:
Cost of Living in Cascais, Portugal
Scroll down to see prices for groceries, meals out, taxi, gas, etc.

Credit Card with Chip

It's a good idea when traveling in Europe to have a credit card with a chip (EMV) - there are some places that only take cards with chips.

When I looked into it, I found a bunch of banks that offer them. In fact, there are cards with chips that have no transaction fee for purchases abroad (usually banks charge 3% or more). 

Note that some cards with a chip use signatures, others PINs:

American travelers' 2012 guide to chip-and-PIN cards on Yahoo Finance

which has a link to American travelers' 2012 guide to chip-and-PIN cards on CreditCard.com

America’s Best EMV “Chip-with-Signature” Credit Cards on Nerdwallet

36 Top Credit Cards Without Foreign-Transaction Fees on Huffington Post (and mentions ones that also have a chip, as well as annual cost and other benefits)

P.S. The Seattle Times Travel section had a short article on May 26 by their editor who tried out a chip card in France. She says that some automated ticket machines in train stations, highway toll booths, gas stations in Europe only take the credit cards with chips. Overall, she says, "Having the card made life much easier" but notes that the Bank of America card she used is "not a true chip-and-pin card (and at least the bank isn’t calling it that any more, now referring to it as simply a chip card). It’s really a chip-and-signature card with the transaction supposedly verified by signing instead of punching in a PIN. That makes it much less secure than a real chip-and-pin credit card, and few merchants ever required a signature from me."

You may also want to read this article about Chip-and-PIN vs. Chip-and-Signature cards.

Layover Time on Return

If you returning via another US city, allow at least 2 hours for your layover to go through Customs. (If you are returning via a European city it's not an issue; you will go through Customs in your home city, because it is your first port of entry.)

Cheap Mobile Phone

I recommend buying a cheap mobile phone, especially for those traveling a week or more. The prices are much lower in Europe (maybe ~20 euros, or $26 for a very basic phone) and you can get a pre-paid SIM with 10 euros of calls for use with it and then "top up" as needed.

There is a Vodaphone store at the Lisbon Airport, in Cascais (both in town and at the big shopping mall, according to the owner of our apartment) and all over Lisbon. (The other mobile-phone providers in Portugal are Optimus and TMN, which I've never heard of; Vodaphone is all over Europe.)

You want a GSM phone, with dual band (900/1800), which is what they sell there but are harder to get in the U.S.

Unlike most US mobile phones, which are tied to a particular service provider (carrier), those phones are unlocked: For other countries, you simply swap out the SIM card. You can keep it for future international travels including Festivals in England, or on return you could sell the phone in the US and probably make a profit, because those phones tend to cost more when bought here.

Vegetarian Restaurants & Portuguese Desserts

As you may have heard, the Portuguese diet has a lot of meat and fish. On the General Info page of the Festival website:
"Portuguese food is not typically vegetarian, however, there are always vegetarian options available. We are in discussions with local restaurants to ensure that the local restaurants have vegetarian options available. For those with a sweet tooth, Portugal’s pastries are legendary as is the coffee which is very short and very strong!"

LuckyCow Cascais Vegetarian & Vegan Restaurants, which I've referred to for a few trips in Europe, as they have wide coverage
TripAdvisor List of Cascais Vegetarian & Vegan Restaurants - note the filters in the left sidebar for various cuisines, price, etc.

Lisbon Vegetarian Restaurants on LuckyCow
Lisbon Vegtarian Restaurants on GoLisbon
Lisbon Vegetarian Restaurants on TripAdvisor

For dessert, take a look at this interesting article with photos: Sweet, sweet Portuguese cakes and desserts. That writer also has a separate page for the most famous Portuguese dessert, patel de nata, which says in part: "Many of Portugal’s best cakes were originally baked by monks and nuns, and the original recipe for pastéis de nata came from the monks at the Jerónimos Monastery in Belem, Lisbon. These days, people queue outside the most famous specialist bakery Casa Pastéis de Belém in Lisbon which began producing these cakes using the monks’ secret recipe after Portugal’s monasteries and convents were closed down in the 19th century."

Safety Abroad

General
Rick Steves has some excellent general safety advice for travelers or you can find similar tips at various websites, including the U.S. Government's Travel Advisory website before going anywhere; none of these countries is currently on the list. There are also links to safety and health tips for traveling abroad.

Portugal
Portugal is considered a safe country, but it is good to be aware of potential safety problems so that you can greatly lower your risk.
The State Dept website has definitive information about Portugal, which begins "Your greatest crime risk is becoming a target of pickpockets and purse snatchers, particularly at popular tourist sites and restaurants, or on public transportation. ... "
If you are going to Lisbon, the site lists additional details.
I read elsewhere that "pickpockets operate in teams: one distracts the victim while the other targets laptop bags or wallets. Being aware of your surroundings greatly reduces this risk and ensures your safety."
ATM security; Try to withdraw money earlier in the day and try to avoid withdrawing money in some of the train stations late at night, especially Cais do Sodre.
MasterCard has some good tips about ATM safety, particularly the Safety 101 section.

Portuguese the Language

I have read in various places that it's not necessary to learn Portuguese because most people speak English, especially in tourist areas like Cascais and Lisbon.
One person commented online that "You can guess the meaning of many written Portuguese words if you know Spanish or any other Romance language, but [spoken] Portuguese is nothing like Spanish or French or Italian" and is different from Brazilian Portuguese, even in spelling and terminology.

It is always considerate - and an enjoyable part of travel abroad - to at least try to learn a few words of the local language. Usually even if your pronunciation isn't perfect, people appreciate your effort. On YouTube there are various videos for learning basic European Portuguese, including this one called Portuguese 101 - Common Words & Phrases - Level One that has useful phrases for travelers.

Luckily the Seattle Sangha have Michel, who offered to translate for us because he lived in Portugal for 3 years.

Biking Around Cascais

Biking is said to be wonderful along the beaches in and around Cascais.

There are supposedly free single-speed bikes available in Cascais thru a program called BiCas.

Travelers commenting on the web have widely different opinions about the quality of the bikes, but everyone seems to agree that biking is wonderful along the coast.

(To see photos of the promenade, see Walking between Cascais and Estoril)

You can also rent bikes, or scooters.

BikePlan - 15€ per day, 50€ per week

I'm sure there are others too. 

You may see reference to Xbike but now seems to be a shirt manufacturer!

Probably want to check with the tourist office in Cascais, because some of the info on the web seems out of date.

This website has a nice map of a route from Sinta to Cascias.

Sintra - Cascais cycling map

I stumbled on this map, which can show routes and topography, among other factors:

There are some fun features to play with.

Bus Info for Cascais

Scotturb runs buses to beaches and sights in Cascais and Sintra.
Scroll down to see the list of destinations, then click on a route number to see the timetable and route details.