I've been working with translation for ages... firstly with an agency from the mid seventies to the early eighties as a job handler - placing work, checking work, and generally learning the business of translating (with an excellent mentor). Since then I have been translating freelance. I still love it - in fact more and more since the Internet has meant it's no longer always necessary to ask the client for background information...
I generally have as much work as I need, but - having done a certain amount of geological research over the last few years - I would happily find space for a nice chunky piece of work in that field.
Having said that, though, one of the great things about being a translator is getting the unexpected jobs, the ones that make you find out about the strangest subjects... It's not a bad way to make a living.