Ok, so being a Canadian I don't know much about write-in ballots (since we don't have them here) but since a lot of people here who live in Arkansas (I feel for ya, I really do) are saying they won't vote for Lincoln (and I don't blame them) why not write-in Bill Halter's name instead?
As far as I can tell with my 5 minute Google search Write-In voting is allowed in Arkansas, this website from Arkansas.gov lists the procedure for write-in voting.
Q: A candidate that I admire is conducting a write-in campaign. She is printing adhesive labels for us to put on our ballots to vote for her. Will my vote count if I use her adhesive label?
A: No. All write-in votes must be written in the handwriting of the person casting the vote. (ACA 7-5-315)
Which is kind of a stupid policy because it would disenfranchise the illiterate, but that's an argument for another day.
The point is if write-in voting is allowed in Arkansas those people who won't vote for Lincoln should instead vote for Halter as a write-in. Send an even louder message to the establishment there that you're not happy with the presented choice of, to paraphrase Lewis Black: "Two bowls of shit, and the only difference is the smell."
I mean, most people I've seen already think John Boozman is going to win in a cakewalk anyway, so why not hand the DINO an even bigger defeat and have the satisfaction of voting for a real progressive all at the same time? I do it all the time, in my Canadian federal and provincial riding my chosen party is never competitive, but I vote for them anyway, because I'd rather have a soul than not.