Custom Firmware allows you to run things like: themes,homebrew games and apps. I will also show you how to install it. The latest version is 5.00 m33-4. you can also donwload that when you have the lowest cfw on your psp.
Instructions:
These instruction will show you how to install cfw with {Catb50 Team's Magic Memory Stick Creator }
The following vidoes will show you step by step three vidoes how to install CFW
Buy the Pandora tool battery at: http://www.pandorabatterybuys.com/pandora-battery-for-psp-10002000-fat-or-slim-co10002000.html?gclid=CLDXnpjA35cCFSYMDQodDWTuDQ
Download Catb50 Team's Magic Memory Stick Creator at: http://www.sendspace.com/file/oe5v0f
There all by the same guy so you won't get lost or miss anything.
PART 1:
PART 2
PART 3:
When you are finish check out some of the cool things that you can do with Custom firmware at: http://forums.afterdawn.com/thread_view.cfm/577632
How to find it it worked...
1. go to system setting
2. go to system information
3. then it says system software. it should look like this.

NOTE: We are not responcible for anything broken or lost or bricked.