Single digital input data logger with USB. Any existing modules?

I'm looking for a compact module for monitoring the state of a switch over a couple of months. just needs to be able to log the date/time when the switch toggles, and store for later retrieval via USB.

I would expect that something like this exists already. My Googling only turns up more complex units. Anyone know of such a device?

Sparkfun sells a number of dataloggers, but not sure if any are USB. www.sparkfun.com

Hi. What's your price range? Is this a remote application where you need batteries?
On one hand, monitoring a switch is really simple. On the other hand, having USB and implementing an accurate real time clock (RTC) is not so simple. There are processors out there that actually have RTC built into them. You just add an external clock crystal to two pins. Then again, these are usually used on complex modules/single board computers, and so become pricey.

later.
kenjj