i know there is another thread somewhere around but it is a little hard to understand, here is a step by step guide on how to get Starcraft 2 working without a beta key (AI only)
1. Download Starcraft 2 Starcraft 2 Beta Client US Build 13891 (download torrent) - TPB
2. Install and patch it up to latest version (patching works in the same way as WoW does, open the launcher and let it load)
3. Download the crack SC2 Beta - Offline Sandbox [FIXED ZIP] (download torrent) - TPB
4. Download some Maps: StarCraft 2 | Nibbits (Only download maps with AI in their name) and put them somewhere like desktop.
5. Run Lazylaunch (was in the Crack rar) and select a map you want to play
6. the game will load, it will set you up as a random race, if you dont like the race you are just go to menu and click restart, it will randomly select a new one.