This is a huge concern for me as I’m a pure paperless guy - no cash if I can at all avoid it. Naturally, there are fees almost every where you turn: International Service Fees, Currency Exchange fees, banking financial fees, merchant fees, outside of network penalties, and more.
But, for Georgetown Students, there’s a card nearby that helps to keep these costs down…
Comparison of my current (and other institutions’) cards:

USAA Platinum Debit & Credit Cards - Both of these have fees from the card company (Mastercard) and the banking institution itself (USAA) to the tune of 5% of the price in the end. On top of that, there are minimum fees associated with purchasing abroad, such as $2-4 on every purchase involving an exchange of foreign currency. I did a rough math calculation and decided $200+ in fees wasn’t worth the effort. The good news is that USAA reimburses you up to $15/month for fees when using other banks’ ATMs - a plus for all those ATMs abroad!

Capital One Venture Cards - With the exception of Capital One, all major credit card companies charge international transaction fees that range from 2-5%. Capital One doesn’t charge foreign transaction fees or exchange rate ones. On top of that, it even gives you the customary percentage back in rewards on your foreign purchases! If I owned this one, or had the time to get it fast enough, I would - look out for a card with no annual fees and a little wiggle room on the payment date (since you might not have internet abroad at that time to check/move your funds).

GUASFCU Visa Debit Card - This is definitely the silver medal in this contest, second only to the Capitol One Venture cards. If you don’t have one already as a student, sign up now! GUASFCU itself doesn’t charge any foreign transaction fees, but Visa charges just a 1% International Service Assessment (ISA) fee on purchases made in foreign currency (it uses a daily spot rate for the exchange ratio) and an even smaller 0.8% ISA fee on purchases made in USD$ abroad. As an example, if you spent $7000 in foreign currency over the whole summer, you would only pay $70 in fees. For the convenience of the plastic card, that’s a pretty good deal to me. Other than that, GUASFCU charges a $1.00 fee on their end (in addition to any fees they may be charged from the ATM itself - which are usually much higher).
From the above comparison, I’ll be using my GUASFCU card to purchase items abroad and my USAA card to access ATMs. Together, I should be able to minimize fees and maximize my purchasing power :) Euro-souvenirs, HERE I COME!