If you need to format a memory stick for your Sony PSP, here's how to do it.

1. Install the memory stick in your PSP.
2. Push the "Home" button, just below the lower lefthand corner of the screen.
3. Repeatedly press the left arrow button until you are in the "Settings" selected.
4. Press the arrow key repeatedly to select "System Settings". Once it is selected, press the "X" button.
5. Press the arrow key repeatedly to select "Format Memory Stick". Once it is selected, press the "X" button.
6. Confirm that you really want to do this.

You now have a fresh memory card formatted for use in your PSP.