iPod touch iOS 4.1 v jailbreaking

I recently upgraded my ipod touch from iOS 3.1.3 to 4.1. I'd waited as I was experimenting with the additional facilities available through jailbreaking but as my iPod was low on space and beginning to run very slowly I decided to upgrade and see what Apple had improved.

the first thing I noticed when upgrading to iOS 4.1 is that my 8gb iPod now only has…