Well, perhaps it would also be appropriate to mention, though, that compiling programs for your N900 is not exactly a walk in the park or anything that a normal user is "expected to do". This is not the way users should install applications and, frankly, it is well beyond the capabilities of most users anyway.

If you're interested in getting some of your favourtie Linux software to work on the N900, the best thing to do is to first of all wait until the device comes out (any day now..., and then start following these forums and the Maemo.org downloads lists to see what is and what should be up on the repositories soon. The repositories are how software should be installed. If you're thinking of a program and wondering why it's not available, start a new thread here. Somebody else, more tech-savvy perhaps, might get interested and start working on it.

So basically I suggest you browse what is available now and see what might be available soon. Don't assume that just because a program is available on Ubuntu/Debian, it'll be easy to get to work on the N900.