Having grabbed a HTC Advantage X7510 Windows 6.1 tablet-device from out of a skip, and finding it working, I set about looking for things I could practically do with it.
Given it's touch-screen capability, and large screen generally, it lent itself to being a Sat-Nav device, especially when I found out it also had a GPS receiver built-in.
Trawling the 'Net, I found "Navigator Free" at http://navigatorfree.mapfactor.com/en/, installed it and I was away. I can heartily recommend it for anyone with a Windows Mobile / PocketPC device who wants to run a Sat-Nav program. The one thing it doesn't do is speak the names of the actual roads, which is a minor let-down compared to Nokia's "Drive" Sat-Nav mapping tool, and which they give away free now.
I was using that happily on a Nokia E5 device, and it's a bit of a trade-off between that, and the larger screen, and ease of use of Navigator Free. Currently, I'm enjoying the bigger screen on the X7510. ;-)
Since finding out more about how the software uses http://www.openstreetmap.org/ to get it's map data, I thought I ought to register and "do my bit", and I've been merrily mapping away, doing the houses in my own street, updating tags on the local roads to me, and doing the local shops around Springfield, Chelmsford, Essex. UK.
I've dived straight in with Potlatch and have found it relatively easy to add buildings, tags, parking areas and the like.
Might have a crack with that local install software next. ;-)