My most ambitious campaign website (described in TT’s second post ever, Running a Campaign Website) included online versions of all of the PCs. I made up a little text form for my players to fill in and update between sessions, and then converted them to HTML for the site. This worked very well — when someone forgets their sheet, or needed to play another player’s PC (our solution for absentees), their stats were there.
I haven’t tried it out, but RPG Web Profiler looks like a much better solution (and it’s free!). It allows you to post sheets online and limit access as you see fit — one person, a few people, the whole world. Has anyone tried this service out?