I guess I'm just old school, but my solution to this problem has been a 250 GB external drive + CVS for all my files. I've been doing it for years and it works great. Every time I leave a machine, it's just 'cvs commit -m "Leaving home/work/library/Starbucks"'. Once you get past the perverse feeling of checking your music library into CVS, it works fine.
My sibling commenter is giving me too much credit - I started before git came along, so it was either CVS or SVN. I wanted to be able to kill directories directly from the repository, so CVS it was.
