Intocombat's
Circuit Training for Boxing dvd has a few drills on it, I haven't had chance to try them but can describe them for you.
1. Basically hopping round the outside dots in a U shape.
X----0
--0 --
X----0
X----X
--0--
0----0
0----X
-- 0--
0----X
where X is your foot obviously.
2. Starting with your feet on two corner dots along one side, hop forward so both feet are on the centre dot and then forward again so both feet are on the opposite sides corners. Go backwards to starting postion and repeat.
X----X
--0 --
0----0
0----0
--XX-
0----0
0----0
-- 0--
X----X
They dont mention any particualr instructions from what I remember, however by watching the vidoe I would say that foot speed is import (obviously) and also the height of the jumps are small (feet barely seem to leave the floor)
Hope this helps.