After you have jailbroken your ipod touch 2.x what you wanna do is 

1.Log into WinSCP (windows) or Cyberduck (Mac) 
If you don't know how to do this -

Code:

http://www.youtube.com/watch?v=YtfjDHfqXWQ

2.Create a folder called Documents in /var/mobile/ and set permission to 777. 
3.Create a folder called Documents in the /Applications folder and set permissions to 777. 
4.Now go to root /System/Library/PrivateFrameworks/Mobile Installation.framework 
5.Replace the MobileInstallation file and set the permissions 775 for the file 
6.Reboot your iPhone/iPod Touch-IMPORTANT! 
7.Download cracked Games and Apps. 
8.Download at least one App from t he App Store(Free or Paid) 
IMPORTANT: Otherwise you will get an error! (Only need to do this once] 
9.Double click on the cracked .ipa you downloaded, and iTunes Should Open And Then Just Sync your iPhone/iPod Touch and enjoy! 

You Set Permission by right clicking and choosing properties, you wont miss it 
HERE IS THE MOBILEINSTALLATION FILE: 

Code:

http://rapidshare.com/files/148053500/MobileInstallation.rar

Enjoy