I was trying what is listed here http://forums.macrumors.com/showpost.php?p=6055900&postcount=161

1. Synced the phone to iTunes 7.7.1
2. Then selected the phone in the devices list on iTunes
3. Selected the Applications Tab and unchecked “Sync Applications”
4. Pressed the Sync button at the bottom of the page which then removed all apps from the phone.
5. After that was done a few apps were still left on the phone so I deleted them on the phone itself.
6. I disconnected the phone from the USB cable and powered it off then powered it back on.
7. When the phone started up I then was able to get to my music and videos on the iPod part on the phone.
8. then uninstalled iTunes 7.7.1 from my PC and rebooted the PC……..

I got through step 7, and then decided to try something less drastic. I only selected the applications I really wanted (and was using) on the iPhone. I had about 80 apps loaded. I used iTunes, (on Vista, … sorry ) and only 71!!! applications I liked.

Wow, now everything works again…Only took about an hour!