I'm running Mac OS X version 10.7.2.
There's this app called app-zapper. It helps to remove the library and cache files from apps when you want to get rid of an app by "zapping" it. I needed to shave some space. I'm using Pixelmator now instead of Photoshop, so I tried to zap my Adobe folder but instead my App Store app got zapped. I didn't realize it till my trash was emptied. The rest writes itself.
I've tried reinstalling 10.7.2, extracting the App Store.app file from 10.7.2 package (it's incomplete) and re-downloading the snow leopard extracted one (don't work on lion).
How can I re-install the app store?