IOS – find just the apps which I have purchased in the App Store

To see a listing of all the apps you have purchased or downloaded, do this :

1. Go to Store > View My Account
2. Login
3. Click on "Purchase History"

You should now see all the apps you have downloaded before.

Stolen from caliban's answer here.

I am running Lion (10.7.2), and there is an x just to the left of the Install / Installed button when you hover over the item in the purchased list. Click it for each App you do not want listed. I don't believe this uninstalls the App, merely removes it from the list. I did this to a program I actually wanted in the list, I don't recall even being asked for confirmation.

Now as far as getting a purchased App back onto your purchased list, that is another issue, and another question.