I have used SnagIt off and on over the past few years, usually with the trial version for a month here and there, finally broke down and got a license.
It runs $39.95 for single user - so I did a quick google search to see if any promotional codes were available and came across one - the promotional code SNUG will get you $10.00 off the standard price. The posting I found for this discount was from 2007 and it is now May 2008 so who knows how long it will be around?
SnagIt is a great tool - if you have never used it I recommend downloading the trial, best screen capture tool ever!
UPDATE 2009-01-07: the promo code SNUG expired on 2008-12-31, bummer; it was great while it lasted!