I still think an accelerometer is what you want (see my post above). Anyone here want to take a crack at designing a simple yet workable circuit using one for the O.P.?
According to the data sheet it can stop in either normally open or normally closed. Does yours work that way? I envision a little ball that can bridge two contacts or stop between the contacts. If that's how it works we can probably work something simple out. Play with it in different orientations.
Yeah, I think that's probably the simplest (and cheapest!) solution! Will hit up Maplins this weekend and see what they've got. Any recommendations? (I'm trying to avoid Rapid again for a while at least as their delivery costs are nothing short of robbery - £7 for a bloody padded envelope and first class stamp!!!!).
That won't work; it only inverts the orientation problem. What you need is a circuit that senses the change ( ac coupled ) and rectifies it ( diode bridge ) But I know you don't want to go to that extreem, so I don't have a good solution.