that's really it. The iPod accessories are starting to get way out of hand. These bags by Soldius feature solar panes that connect to an integrated iPod dock
(you can connect your cell phone as well). Prices range from $200US to $800.
For $800, I had better get Rodney Dangerfield's bag from Caddyshack that plays music (via the iPod, of course) and ejects my clubs via compressed air.