When placing a bounty I should be able to leave a comment along with it. The comment would be sent to the target in the "X has placed a bounty on you" event, and it should also be visible to anyone looking at the bounty listings.
This would be an endless source of entertainment.
This would let me place a bounty on DUDE, for example, and she and the rest of the world would know that it's because "She won't stop creating terrible threads in General Discussion."