The stuff I prefer to use is just like what a lot of the operators and bow hunters have taken to using, BowFlage by HS Camo. Comes in little aerosol cans and unfortunately costs about 5 bucks a can, good thing is that it comes in a wide variety of colors and it's removable which is a big plus to those who change patterns as the seasons or environment changes.
I mentioned it in the other thread that in the US Navy television commercials where they promote the SEALs you can see a couple of pieces of footage where they're carrying camo'd M4s and M16s. After being familiarized with the BowFlage colors I'd say that the guns they have in that footage is pretty likely wearing BowFlage paint.
here's my AR10 which I intended to have blend in with woodland BDUs while my 20inch Bushmaster is intended for 3 color desert BDUs
[img]http://home.bak.rr.com/varmintcong/AR10A4od.jpg[/img]
[img]http://home.bak.rr.com/varmintcong/AR10A4lft.jpg[/img]
There are a couple other guys on the forums that have used the same product with similar results, some of their patterns are the "leaf" layouts while others go for a dispersal pattern similar to BDU style camo.