linda perry, the singer from 4NB also had a solo album, but commercially, it didn't do very well. i think she also had a song on the soundtrack for the second crow movie.
johnette napolitano from CB had a couple of side projects, one was called vowel movement. i think maybe 10 or 15 people actually bought that one. the other was a band called pretty & twisted. they got a little bit of airplay, but not much.