I made up some neat, relatively permanent copper tags for my hops using copper sheeting I bought from a local metal supply. The copper cost me $8.40, but the sheet's original purpose was to space the coils of my immersion chiller (this is what I did with the scrap).
I got this idea from pilotdane: http://www.homebrewtalk.com/f92/2009...ml#post1326163
I bought a stamp set from HF and stamped the hops names into the copper (I clamped a 2x4 on top to line it up). The letters are 1/4" high and centered on the 3/4" tag. I folded an additional 1/4" around the back to give it a little more strength. To attach the 10 AWG wire, I fluxed the wire and a line on the back of the tag and soldered it with a propane torch.
One sign next to my Cascade.