How can I format the Sony PSP Memory Stick.

You can format any size Memory Stick Sony PSP, as follows:

First click the little house in the lower left corner of the front panel.
Use the arrow keys to move to the second parameter, then up and down buttons until you find the system settings.
Third, if you click on "X" button, scroll up or down to find the Memory Stick format. Click the "X" button, re-select this option.
Fourth Sony PSP now confirm that format you want to select the memory card (delete all files and save the game theme, of course), so it is only a few seconds.

should now that you have a new memory stick cleaning is no problem, music, photos or other information you can find a copy of your PSP.