For those who cannot afford to study abroad or who cannot do a teaching assistantship in Europe because they don’t have foreign language skills:
Travel and/or work in Anglophone countries: Work and Holiday Visas are a way to travel to a country for more than 3 months, and possibly work (legally!) to help fund your travels. The only problem is that many of them have age restrictions (for example, between 18 and 30), you cannot bring your dependents along with you (if you have any), and you must have enough money to begin with to prove that you can survive and go home in the end. Some also require that you still be a student or a recent college graduate.
Anywork Anywhere allows you to choose your country of origin so you can find out which work and holiday visas are available to you. For American citizens, the only actual work and holiday visa agreements are with Australia (though the site hasn’t been updated to indicate this yet – it was just created October 31, 2007) and New Zealand; but there are other work and travel programs in the UK, Ireland, and Canada.
BUNAC is another site for work and travel programs in Anglophone countries (but only for those from the UK, Ireland or USA), as well as volunteer and teaching opportunities.