Thanks for the great ideas guys!
I guess at this point I should elaborate on what I'm trying to do here, which is using mouse gestures for side-scrolling melee combat, and Black and White was the best example of mouse gestures in a game that came to mind. My reason for this is to try and keep the combat more skill based (as in, the human player's prowess) as opposed to being level/gear based which I figure could make for an interesting multiplayer scenario or even as a single player campaign - also it is theoretically more immersive. It's very much a WIP so I'm trying the gestures as a proof of concept... If it doesn't work I'll try something else but that is for another thread.
In any case, sounds like there's definitely some scope here for experimentation and maybe a chance to make an open source complex-gestures library of some sort while I'm at it
If there are any further ideas or interesting links do post them here! I'll go away and see what I can come up with.