Fiberfix Emergency Kevlar spoke repair can be used without removing the freewheel, even on the drive side. You can leave it on permanently, or do a real spoke replacement at home at your leisure. I've used it twice on rides. Takes about 5 minutes if you practice first. Only problem is sometimes the broken spoke is hard to remove. Harris Cyclery carries them (no connection...).
L'Hitraot,
Josh Berger
Bronx, NY