1. Forth family languages like Factor: I'd love to be forced to learn that stack-based insanity. I'm really impressed by how concise GOOD Factor code is. Seems like a long shot, but I said it. And now you're thinking it!
2. Clojure and to a lesser extent any Lisp: I'd like to learn "The Clojure Way" of Lisp on a project; I'm a CL hobbyist and have a good/great grasp of macro-fu, but I'd like to be in an environment that encourages idiomatic Clojure, to learn how refs and other Clojure features change your approach to a problem. And since I've never collaborated on a Lisp project with others, I'd love to have that opportunity as well.
29-year-old crapware refugee turned Ruby contractor, currently living in the middle of a beautiful nowhere.
Stayed with a friend in Harvard Square to attend the first startup school, and to pester a couple of very nice SFP founders, including the Kikos, about what they would do if they lived in the middle of nowhere and had no co-founder. I know, I know.
I spend 9 months of each year in remote Pacific South America, doing volunteer work - and surfing, quite a lot during the good season!
Like pg says, lots of good projects, to really do them right, have to be companies. For that reason I can´t rule out doing a startup. But it would have to be pretty good, because it has a lot to compete with.
When I am in the United States, I am always up for short/medium term on-site work.
npm install macros.coffee -- 100-line prototype of lisp-style macros in CoffeeScript.
Update: I came back to the United States to get married, and I'm living in Minnesota for the next couple of years until we feel ready to move down south. Hit me up for work from August through February.