Type "ppm" at the command prompt and the GUI will start. No need to use the older command line version of this. Once DB sync is done, you have a list of all packages on all repositories that are available,upgradeable, etc.

Go to Edit|Preferences|Repositories to modify the places that PPM looks at. It will be faster with fewer repositories.

Update: I just ran this thing 5 times. It sync's with the ActiveState repository very fast (some 5-10 seconds with repeated starts...I guess it knows if there is something new there or not). It could possibly be that one of your repositories is slow and this hangs things up? Anyway once the GUI syncs, the "search" is sub-second fast as all data is resident on your computer.