One of my students has been having right hand trouble lately. At first she thought it was a right hand position problem, so for months she worked on changing her hand position to one that would enable her to play smoothly. As the problem continued, though, we gradually realized it was not a position problem but a physiological one. She went to a chiropractor who discovered she had a pinched nerve in her neck that was causing the lack of control she was experiencing in her right hand. Since it takes months for that kind of thing to be treated, we were looking for alternative things to do until she sees physical improvement.
One of the ideas she had was to use a flatpick instead of fingerpicks. I was heartily in support of this idea. I have heard a banjo flatpicked Scruggs-style (by none other than David McLaughlin) and it sounds strangely cool. Two weeks ago I gave her a flatpick and we went through the rolls and a few of the beginning tunes ("Banjo in the Hollow", "Cripple Creek", "Foggy Mtn. Breakdown"). When she came back the next week she was playing with ease, albeit slowly. The strings on a banjo are pretty far apart compared to other instruments regularly played with a flatpick.
I realized that this would be a brilliant exercise for any student. You have to know your rolls cold in order to play all the same notes with a flatpick as you do with your fingerpicks. Try it. Play through "Banjo in the Hollow" with a flatpick (or your whatever your easiest song is) and see if you can do it. It sounds pretty neat and is a brilliant brain exercise.