Behringer Composer MDX2100 compressor.
This is a cheap compressor, it sounds a bit better than the Alesis 3630 I had before but the gates are a lot slower. I just use it to compress vocals and for the occassional special effect.
EXAMPLE SOUNDS
MDX2100 - TR-909 loop from the K2000 through increasing amounts of compression.
LINKS
Harmony Central reviews here