In his left shirt pocket, we see his pocket protector with pens, pencils, and note paper. In his right shirt pocket is a pocket coordinator -- maybe a Palm Pilot (tm) or something of that nature. Note the thick glasses with thick rims. Sadly, medical tape is hard to draw.
You'll also note his polka-dot tie. His tie will change with the seasons. This is pretty sane for Dave. Also, note the cellular phone. It is a permanent part of his image. Finally, note that his right pants pocket bulges somewhat. In a future strip, you will see his wad of keys.
As you might guess, this character is patterned loosely after the author of the strip, although much geekier. Dave's goal is to be more like Mike. (Don't you dare start singing.)