Having worked in geophxsics, I feel fluent in GPS and maps, but still somewhat beginner with OSM.

Main areas of interest:

• Central Laos (Khammouane province)
• Mljet (western part) and Slano (Croatia)
• Grevesmuehlen (Germany)
• greater Potsdam area (Germany)

Mostly doing OSMapping while cycling, or geocaching :P

• power lines (also minor ones)
• hiking and cycling routes