My favourite colorscheme for vim (Jellybeans.vim recently had a pull request submitted including a colorscheme for iTerm2, a terminal emulator for OSX.
Not wanting to go back to OSX after finally getting my encryption key back and being back in linux, I set about converting it to RGB values that urxvt can understand.
I realised two things while doing this-
1. plists are flaming piles of horror. Someone at Apple took bad acid.
2. Ruby is cool for bashing up quick scripts.
The results are up on github as itermcolors2xdefaults and it seems to work reasonably well.
The scheme in question was very feint so I added an option to multiply all the colors, but by and large it does what it says on the tin.