I found this guy's YouTube page - he offers some lessons in basslines. They're good viewing and can help to increase your riff library, but as I was watching him, some of his explanations were a little weird (not very user-friendly). Makes me really appreciate the way Roy explains his lessons and - most of all - the TMBG real time fretboard.
That having been said, check out this guy's lesson list. There might be something in there you can use!