To use it, place yourself in front of the webcam at a reasonable distance and start taking pictures. You can edit them in many different ways by using special frames and all sorts of layouts.
Once you're done taking pictures, you can automatically upload the results to Facebook, img.ly, Mobypicture, Posterous, ScreenTweet, TweetPhoto, TwitDoc, Twitgoo, TwitPic, twitprix, TwitSnaps, or Tumblr. You can also print them right away if you want to.
Party Booth is an interesting application even if it's not particularly useful. Although the pictures it takes are a lot of fun, you can easily do the same thing with other applications.
The trial version can only be used for seven days.