I'm getting ready to take the PMP in a little while, and so I've recently gone through the exercise of documenting all of my PM experience to meet the requirements for the PMP application. There are several helpful websites and templates that I found. I looked at a few of them, and ended up creating my own custom version of an Excel spreadsheet for use in documenting my time in PM.
If you want to check it out, click the image below to download it.