The Vote It Up plugin enables visitors to vote for and against posts.
A working WordPress install
WordPress theme must contain a call to the
WordPress theme must contain the WordPress loop
Most WordPress installs have these, so you need not worry about these.
WordPress 2.8 or above is recommended for this plugin.
votingfunctions.php, there are several functions that can shows other information.
Returns the number of votes associated with the post.
Returns TRUE if the user already voted for the post, FALSE if the user hasn't voted for the post
Returns an array of user IDs that have voted for the post.
Returns an array of user IDs that have voted against the post.
Returns an array of post IDs and votes. The array is sorted with the post having the most votes at the top of the array.