I like to hike around Thimphu and have a HTC HD I use as GPS. Most of the fun so far is checking the altitude but, recognising where I am would also be nice.
On my HTC (Mobile Windows) I use the GCC app and the documentation that came with the app recommends OSM as source of maps. Actually, I need tiles. So here starts the adventure of downloading tiles on my HTC... And seeing on my HTC what I could see when I look around.