Reply to A better iTunes?

Like many iTunes is my base for 'holding' my music. I use a combo of genre, bpm, and star rating fields to filter my music into lots of smart playlists to help organize my music for dj stuff....

Ok my question is... Is there an app where I can edit song tags like genre and bpm for iPhone? Or better yet, make or modify playlists?

I would love to organize and modify songs while away from my computer. Right now I use star rating, 1 star = trash me, 5 stars = look at me, look at me!

Any ideas?