Warning: there are 20 images contained in this blog post!
The 20 puzzles are presented in random order below. To encourage readers to vote honestly for the puzzles they like the most, and not merely for the author they like the most, I have withheld all of the authors' names. Please take a look at them, solve them, and email me (glmathgrant[at]gmail[dot]com) up to four puzzles for which you'd like to cast your vote. In order to encourage the constructors to participate in the voting, constructors are allowed to cast up to five votes, and may vote for their own puzzle if (and only if) they choose to use all five votes.
Because of this unprecedented level of response, I imagine that it would take a diligent reader much longer to solve and evaluate them all. . . so I have extended the voting period from the planned four weeks to eight weeks! You will have until September 29, 2011 to send in your votes; the day after that, the winner will be announced. If there is a tie, I shall cast the deciding vote. Note that one of the puzzles above is mine; if my puzzle ends up being the most popular, then I will receive a gigantic ego boost, but I am ineligible to win any other prize from this contest.
