You may be running out of disk space.
The iphone/itouch has its hard drive partitioned in two sections.
One smaller partition is where the apps are installed and the larger is for the data.
Eventually if you install many apps, the partition will fill up.
To fix this you can install bosstools which allows you to move apps to the larger partition or you can move the fonts which is takes up a lot of disk space.
If you use the bosstools app you should be able to install many many more apps.
I cant activate Hidepod. I used one of those "Gift Credit Cards", and it worked, but it said after I clicked the "Buy" button, that the seller only ships to confirmed addresses.
hidepod works perfectly for me all you have to do is after u hid the videos just delete them from your ipod app and i could still download 3rd party apps