I printed this on a Makerbot Replicator in ABS.

The model contains integrated supports for the overhangs, and thus is designed to be printed without support. The one in the pictures was sliced at 0.15mm in Skeinforge 50, but I believe the default 0.27mm layer height should print fine as well.

After printing the two support sections can be broken off easily by hand. Then a little clean-up to cut or sandpaper off any support that remains is all that should be required.

The method I used to design in the support material and a variety of previous failures is documented at atomsandelectrons.com/blog/2012/10/battling-gravity/