Just stumbled over this

http://www.dissidentlogic.com/images/NormalOffsetShadows/GDC_Poster_NormalOffset.png
main site: http://www.dissidentlogic.com/#Normal Offset GDC Materials

Pretty awesome technique to get rid of shadow acne!
Needs a little extra work for a deferred environment though, as you can't really use the "high quality" normalmapped normals from the gbuffer

Works out of the box in forward shading though and is a nice improvement to A8's PSSM shadows.