Phpbb is rubbish I agree.
Shame someone hasnt thought (I haven't checked) of a pandora market, not for selling apps but for downloading direct to the pandora.
It would be very useful. although you could prolly do some web app like that and just browse for it on the pandora...
But I was thinking of more of a pandora app that does it. p&|a as seen on the wii homebrew channel.
Trouble with app downloading is that root folders get messy quite quickly. it would be great if the app also sorted the extracting of the folder too.. something unified so you don't get multiple folders or catgories.
Just an idea..
As for the website idea make it very simple and basic catagories/sub catagories. something like
http://linuxappfinder.com/ just a bit nicer looking, and less clutter.
maybe something custom would be easier rather than working on often overcrowded prebuilt systems that have too much background stuff going on.