Version 0.7
As requested (by bingsterloot) the plugin now immediately refreshes the count of votes for a given post in response to a user clicking the voting link, rather than displaying a static "thanks" message.
Version 0.6
Thanks to feedback and testing from chandersbs and bingsterloot the plugin was modified to remove the voting link, if you've already voted, and give the option to list out all the users who have said thanks. Thanks also to citizenkeith for testing v0.9.0.6 compatibility (or rather, lack thereof).
Version 0.5
Initial release.