To say that people are looking forward to the PSP Go’s release is an understatement. There are many features that will be on the Go that are not featured in the UMD featured counterparts. The new “Pause Game” feature is just one of those.
This feature essentially allows you to pause your game at any moment of the game, return to the XMB, and resume it at a later time. This is done by clicking an icon that will appear after the option is selected via pressing the PlayStation button.
The game state is even saved if the Go is completely turned off. Eric Lempel was asked if this feature would ever make it to the regular PSPs. Sadly, his official response was that the feature is only available on the Go.
[Source]
