Firmware 3.00 isn't even available on the US website yet, and it looks like there might be a reason for it. 3.01. Gyuh? Yes, in just one day after 3.00's release, Sony has released yet another firmware upgrade: 3.01. It appears Sony somehow discovered a security hole in the firmware hours after the previous major release.
If for some crazy reason, you desperately need to have the latest firmware, and remove the possibility of homebrew on your system, set your PSP to run Network Update. Just know that there's no other benefits to running the update other than this security revision.