Capture GPS data at the flip of a switch

Hello,
I have a need for gathering GPS data based on switch activity. A truck driver will flip one or more of several switches on a dashboard. When a switch(or switches) is(are) flipped, I need to record a waypoint at the position the vehicle is when switch activity occurs. As well, I would need to record which switch was flipped. For example, if switch A is on and I flip switch C on and turn switch A off, data log "GPS waypoint, switch C on, switch A off". Or if switch B is on, and I flip switch A on without flipping switch B off, data log "GPS waypoint, switch A on". Then if I flip both switch A and B off and flip switch C on, data log "GPS waypoint, switch A off, switch B off, switch C on". Of course there are many different scenarios but the simplest view is to data log "GPS waypoint, switch, off/on" no matter what scenario occurs.

Hopefully this gives a clear picture of what I'm after.

Any help would be greatly appreciated as I have tried researching this for a solution and have come up empty after several days of effort.

Thanks,
Mr. I

p.s. Note that I am open-ended on the hardware/software configuration. I can go with a GPS-enabled PDA (such as a Garmin product) or a GPS receiver connected to a laptop, or any other similar configuration. If data capture can flow through a data logger then good; if needed to be p****d out and reconciled via software program on laptop then that's ok too. Final results will be plotted in ArcView(most likely) or equivalent.