If you missed out on the start of "Heroes" when it premiered in the fall, you don't have to wait for the DVDs. NBC has put all 18 episodes of the show online for a limited time. Granted, that's a lot of catching up to do if you're starting from scratch, but the show is off the air until April 23, so at least there's time.
The site doesn't say how long the episodes will be available, but when NBC did something similar in December and January, the videos stayed online until new episodes began to air. So, make like time-traveling hero Hiro and jet back to September!