$20 off of purchases of $100+ (w/free shipping) at BeautySak, which currently sells Lippmann for $15, RBL for $18, and Essie Matte About You topcoat for $10. Code: TWENTY (expires: September 13th, 2009).
Two polishes are currently on sale: Lippmann Fashion for $11 and RBL Grunge for $15 (pictured above).