I ended up getting this:
http://www.garmin.com/products/geko201/ for only $59 brand new from Fry's (web special). Couldn't be happier. Does trip, average speed, maximum speed (neat), has a speedometer, etc. Interestingly, I found that my 380SE speedo is fast by about 2 mph whereas all my other vehicles are dead accurate. Really cool, tons of features, and I can take it hiking or use it as a cycle computer. I also bought a map-based step-by-step WAAS enabled voice guidance GPS, but that's another story...