Some of the state issued stamps are really awesome looking ... see link below for some awesome / comical stamp pics
http://www.marijuanastamps.com/
(click on states and then use pull-down to select state to view)
The federal stamps aren't as exciting as some of the state ones, but the fed ones, are on the whole, more valuable, since they're very rare (were never issued) and are uniform in design - what I mean is that are numerous state designs and also some states issued them haphazardly.
Enough of me rambling on ... here's some pics of state stamps from marijuanastamps.com
Don't they mean JUST SAY 'KNOW' LOL!
Ron