My personal interests are:

• Political and administrative borders, both land and maritime, with a focus on high precision and legal accuracy. TIGER boundaries (even of recent vintage) leave a lot to be desired!
• Study of landforms and terrain, particularly the concept of topographic prominence.

I believe imports are the backbone of openstreetmap, and one of the project's primary goals is to aggregate and consolidate the best data out there. Amateur mappers will never match the thoroughness or standards of professional mapping agencies. But not all imports are worth the trouble -- data quality is paramount when deciding what to accept into the map.