I picked up a used bold on craigslist and it's running okay. However I would like to do a COMPLETE format and restore to factory settings just so I have a clean slate if you will.
Options > Security Options > General Settings > press BB/menu button > Wipe Handheld > follow any on-screen instructions.
Also, you could use Jl_Cmder and completely wipe the phone to the point where there is no OS on it, and then download and install a fresh copy of whatever OS you want to use.