That'd be a Mile Marker 10,500lb hydraulic winch, mounted with Hummer mounting plate. Didn't have the money for a custom winch bumper (expensive and hard to find for my year), so I picked up some heavy stock steel and had a guy I know weld it directly to the frame.
After it was done, right after Katrina hit in August '05:
POR-15'd:
Finished (before plate was properly mounted):
My truck has changed appearance a little in the past couple years.