I recently picked up a decent handheld mapping GPS, an invaulable tool for trail riding. While I have a full-featured Garmin Nuvi 760 for the car, and have used it many times on the bike, it's really only useful for street navigation.
So, after much research and lots of online bargain hunting, I ended up with the Garmin Oregon 300 GPS. It comes pre-loaded with a basic worldwide basemap, and I've added Garmin's Topo Canada V4.0 map, cGPSMapper Southern Ontario Enhanced Basemap (free map from http://gpsmapsearch.com/ using this map). I also picked up a 16GB Kingston MicroSD memory card (overkill, yes, but it was only $25), and I even wasted 30 bucks for a subscription to Garmin's Bird'sEye Satellite Immagery web download service (not worth the cash, in my opinion).
Garmin Oregon 300
The Oregon 300's main features include touch screen (3" diagonal), high sensitivity WAAS-enabled GPS receiver (it's accurate to within about 10 feet), electronic compass, barometric altimeter, microSD memory card slot, wireless sharing of your data (waypoints, tracks, routes and geocaches) with other Oregon units. It's also waterproof, which is a very important feature.
I've not had any trouble using the touch screen while wearing my gloves, although it seems to respond a little better when I remove my gloves. So far, I'm really liking this GPS. I bought it at Walmart for $299 (Canada).
screenshot
I bought a RAM mount system from GPSCity through Amazon for $30. The only way to really mount this thing on the bike. Garmin sells a handlebar mount that attaches with zip ties, but it looked pretty crappy compared to this RAM solution.
To power this new GPS, I've been using low self-discharge Sony CycleEnergy hybrid Ni-MH AA batteries. I went to the Sony Store at the mall and bought a kit that includes a charger and four AA cells for $60 -- yikes! The charger has a "refresh" button that will drain the batteries fully first, and then charge them, if you so wish. The advantage offered by newer hybrid types is that they retain their charge for a much longer period when not in use. Older Ni-Mh batteries would lose ~ 1/2 their charge if they weren't used for 30 days. These particular Sony's perform very well when powering electronic devices. Although they don't have the same initial punch as some higher capacity 2700 mAh batteries, they do perform very well and actually last longer overall -- many high capacity rechargeable batteries provide more initial power, but only for a short time, meaning they start to run out of steam quicker. These Sony's provide a good balance of overall lasting power, and they claim to retain 90% of their capacity while in storage for a year. So far, my experience with these batteries is very positive. They have performed much better than many other rechargeables I have used before: I've tried the Energizer AA's and they suck, and Duracell rechargeables are OK, but not nearly as good.
I have some smaller AAA Sanyo Eneloops (also hybrid) and I would have bought some in AA size but I wasn't able to find them locally, I've also used the as these Sony's.
I have also used the mini-USB cable to power the GPS while on the bike using my 12V cigarette lighter plug USB adapter. It works well but I'm worried the extreme vibration from my big thumper might eventually loosen the USB port connnection on the GPS. Besides, these new Sony batteries are easily lasting a full 8-hour day of riding, and I keep a spare set fully charged in my pocket just in case.