This is the one I will be trying when I get around to buying it:
IxizAOSep - Air Oil Separator
http://www.ixizconcept.com/
http://wrxmodders.com/forums/viewtopic.php?t=10101
I know Jay is running this unit on his purple car.
I like a lot of the more innovative parts coming out of smaller companies these days. FWIW, I don't think I fully believe the GrimmSpeed unit works as planned. I can explain why, but it's better to do in person with an engine bay to point to.
EDIT: DAMN! Jay beat me to it.