In reply to Donnie:
For walking, winter climbing, and cycling go for a Garmin GPS map 62s which is second generation GPS unit.
On sale at £229 includes full OS UK 1:50,000 map micro SD card. These were retailing at £540 not long ago.
If you want spend a bit more go for the Garmin GPS map 64s which is third generation GPS unit.
It has some extra bells and whistles including the Russian GLONASS satellite reception.
Price around £350, but cheaper if you can get mountaineering club discount.
The trick is using the correct type batteries with the latest type battery charger. I use NiMH nickel metal hydride rechargeables. There are two types, Ultra High Capacity and Low Self Discharge. Go for the LSD with2500mAh+.
Not so easy to find in supermarkets, but available on websites where you want to buyabattery.
This is my weapon of choice in whiteouts and 16 hour days/nights.
For even better free downloadable digital maps go to the wiki openstreetmap open data base project, or freizeitkarte public domain, 25 metre contour vector format maps. UK, Europe, All Alps. Its a revelation.