How can you prompt the iTunes store to offer the 4.0 software update for the iPod?

Most applications now require at least the 3.0 update, but I can't seem to find it on the iTunes store anymore. I know that they're offering the 4.0 update, now. Help? :]|||plug in your iPod Touch and look at "summary". you should see a button under "version" that says "check for update" click on this and you should start the upgrade process. all of the data on your iPod will be the same as when you started. i have an iPod Touch 8gb 2nd generation, and unfourtunatly i dont get all of the flashy fun things.|||from what i know is you just hook up your ipod touch or iphone to the computer and click sync and i should automaticly offer the new software update. I dont think the 4.0 works for the ipod touch, i know it works for iphone 4, 3gs and 3g.