I needed to be able to see what was on the clipboard for some code I was writing. I could have used the Clipbook Viewer (clipbrd.exe) that used to come with Windows, but it's not there in Windows 7. Even if it was, it hasn't been updated for eons and it's always more fun re-inventing the wheel. So here is my clipboard viewer. It handles most clipboard formats and is pretty easy to extend to support other formats.
Download/view the source
Download the executable (.NET 2 required).