I think I've gone off the deep end!

[Jason]

I suppose I saw the one focal length as a challenge more than a limitation. It would make me think about how I'm composing, and move to get the shot.

Before making the jump for that reason, challenge yourself with what you already have-- I'd really consider using the one that you have while putting the limitation on yourself of not moving the zoom, or if you have a fixed lens, slap it on and don't take it off. See if it works for you--but I know it would drive me nuts!