HIIT Cardio is 'high intensity interval training'. It burns fat faster and in less time than steady-state cardio. It's a way to get the quickest bang for your buck. Here are a few links:

http://www.intervaltraining.net/hiit.html

http://www.bodybuilding.com/fun/bbinfo.php?page=HIIT

http://musclemedia.com/training/hiit.asp

I do HIIT after my lifting routine. I generally do sprints on the treadmill or bike until I'm out of breath followed by a normal pace.