I've used Memory Map with an IPAQ pocket pc for 3 years and can thoroughly recommend it.
Last year I bought a Samsung QI tablet pc running Windows XP, I run Memory Map and/or whatever local topographical charts are available. Some people talk about hard discs failing but I regularly go up to 14'000ft and never had a problem. With the optional power pack it runs at full brightness for over 6 hours. It's fixed to the panel with quick-lock tape.
I now have 'SeeYou Mobile' on the IPAQ, it gives me voice airspace and danger area advance warnings, altitude (hypoxia) reminders, all the navigation info you need, distance, eta etc., terrain collision prediction plus aerial cable and Flarm aircraft collision warnings.
I have 3 independent gps nav systems, you'll probably find it overkill but I used to fly Airbus. It relieves me from the chore of preparing, using and interpreting paper maps, so I'm always looking out with only short glances down at the screens; I think I can honestly say that I usually see others before they see me.