Hi Guys - I mentioned this in the Mountain Lion thread but want to create a different topic for it that's simple to find without wading through that whole thread. When installing apps on Mountain Lion OS X 10.8 you may see an error or message that says the following ->

Your security preferences allow installation of only apps from the Mac App Store and identified developers.

By default Apple has changed the security settings to only allow installation of apps from the Mac App Store and identified developers. To change this permanently or temporarily go to System Preferences > Security & Privacy. On the General Tab click the little lock in the lower left corner to unlock the general preference pane. Then select the Anywhere radio button beneath Allow applications downloaded from: Here are a couple screenshots.