I've been mapping on OpenStreetMap since June 2007, needless to say, I have quickly become addicted!
Most of my mapping is done based on data collected with a Garmin GPS.
Urban mapping especially in Bangkok is based on Yahoo! Aerial Imagery (confirming with GE when better resolution is needed) and on-site confirmation for street names, one-ways, layer of bridges and viaducts...
I always try to be as thorough and accurate as possible. For example, I'd rather stop a road halfway than guess the rest if there's a cloud or a shadow in an image.
My personal favorite mapping : motorway interchanges... don't get a lot of that in Sri Lanka, so Bangkok is a new field of practice. :)
I live there
I spent a few months there
My home country