Depending on where you live and your bank, your branch may keep some Euros on hand. You should call to ask. However, I've found that the exchange rate they provide is crap. Also, if you're an AMEX cardholder and have an AMEX travel location close by, they will exchange. Finally, I've heard that AAA will do this (but not certain of this.)
Regardless, why not just use your ATM card once in Europe to withdrawal euros direct? I've found that the best and cheapest method.