My wife and I are research scientists (microbiologists). We're starting a project for some undergraduates at our university that will involve them going out and taking samples at various sites. We were both kind of thinking that it'd be good for them to use a GPS to record the location of the samples in case we want to go back and do a longitudinal study at one of the sites or go back to that exact location for any reason at a later time.

Since this project is going to be funded by a grant we have, the first thought was to buy a GPS of some sort with the grant. The thing is, they're going to be using it for sampling for about 3 weeks and then it might not ever be used again (there might be others in our department who have one they've bought used a few times and then put in a drawer and I'm going to ask them first to see if there's one laying around). We might do this every year if it's a successful training project, or it might be a one time deal. So I was thinking that this might be a good time for me to get a moderately inexpensive GPS for my bike out of my own pocket and just let the kids use it for those 2-3 weeks (ethically and legally I couldn't use one bought on the grant on my bike for personal use).

If I decide to go the buy one for my own use and let the kids use it for their 3 week sampling exercise, can anyone point me in the direction I need to look? It needs to have precise location tagging (obviously), and beyond that I don't really need a lot. Would like a mapping feature for rides so I could design a route beforehand and it'd tell me when to turn. Speed and distance, obviously. If it could hook into a cadence transmitter, that'd be great, but not essential. Same for altitude and/or slope. Mountable on bars would be essential, of course, but I'm assuming there's a mount for just about everything these days. I'm not a powertap kind of person, so I don't need that sort of functionality. Since I'd be having undergrads use it, it'd need to be fairly rugged and not too outrageously expensive that I'd be out too much if it got broken/lost (I'd love turn by turn directions after input of new address on an edge 800, but that fails this price requirement). Anybody have any suggestions?

I'm in no way shape or form a brand snob that needs something from garmin and would be perfectly willing to go with one of those deal extreme models if they meet my requirements and are reliable enough.