Well, it seems I have gone quite far in the small amount of time since this thread. Not only have I successfully downgraded my PSP from 2.71, I've managed to flash custom firmware, install emulators and homebrew, while also using an application called devhook to make life much easier. I have a custom theme and bootloader as well. I'd love to hear what else I can do with the PSP in terms of customization. Most of the information I used to do everything mentioned was acquired at PSPUpdates. I'd love to answer questions that involve the above mentioned if anyone has a problem running a certain program.
Keep in mind, I went from v2.6>v2.71>v1.5>Custom v1.5.
Firmware - v2.71
Downgrader - v2.71~v1.5
The Ultimate Installer - Devhook
DGEN v1.70 - Genesis Emulator
SNES9xTYL v0.4.2 - SNES Emulator
ThemePSP v1.2 - Apply themes to your PSP!
Harleyg's Custom Firmware v0.2 - Custom firmware that gives you wonderful new features!