I think there are several reasons learning foreign language might be worth the hassle:
1) you are learning language of a place you are moving to. Suddenly you are the 'foreigner' and being able to speak with the local language is a advantage.
2) you are learning a language significant minority of your location. I assume speaking Spanish in the US can be useful. Or speaking $LANGUAGE of neghboring country if you are in a border region. In small-enough country almost anywhere can be considered a border region.
3) you want to impress you foreign friends/clients/colleagues/customers, understand them better.
4) you are studying some artefact from a different culture and want to enjoy the un-translated original. This applies to things from watching your favourite anime in Japanese to learning ancient Greek or Hebrew to read the Bible closer to its origin.
You might find more. But if you don't have the time, or willpower, you can get a long way just by being reasonably humble and polite, in a level appropriate to the culture you are trying to interact with :)
On the other hand, getting to good enough proficiency for the language to actually be useful beyond i.e. asking "Где почтамт?" really slowly, can be quite a hassle.
My suggestion then is to stop thinking of learning foreign languages as a "hassle" and instead think of it as an opportunity to learn about other people and cultures of the world. Not only will you be culturally enriched but you'll also be able to compete and survive in this global economy.
Also - I learnt because I was making online friends in Latin America, and 10 years later I've got friends in just about every Latin American country + Spain, almost none of them English speakers. It hasn't been a 'hassle', it's been amazing, life-transforming. ...Well OK, the subjunctive is a hassle :-)
There are sites like livemocha and lang-8 that match you with people learning your language, so you can teach each other. I haven't been on those sites much - I almost immediately met a great teacher both times I've tried, who became a dear friend, the first in Nicaragua, the second in Spain.
Also I have to say that the word foreign seems very silly and parochial to me. "People from every other country in the world except my own" is a strange category.
Why do you think it is a hassle? Do you plan to never interact with a foreign person?
People open up to you if you can ramble off even couple of sentences in their language. It is absolutely worth the hassle for a traveler.
But if you live in and don't see yourself ever leaving bumfuckville, Alabama, then there's no point.