I have written the following plugins for Squeeze Center 7.0 and higher:

PGA Scores
This plugin displays the results for the current PGA Tour event. You can configure how many players you want to display and also track specific players. The Champions Tour is also available. This plugin uses the API provided by the SuperDateTime screensaver plugin.

College Hockey
This plugin displays the scores of your favorite college hockey teams. You can choose up to 2 teams to follow. Updates during the games are sometimes scarce but normally you'll get end of period and final scores. This plugin uses the API provided by the SuperDateTime screensaver plugin.