Some are real...but it's definetly not FREE.
For example, you may have to complete 5 "sponsor offers" of which might include; opening a credit card and buying something with it, ordering vitamins and trying them, ordering a DVD from a rental website, and...what's another popular one...OH! Getting 3 of your friends to sign up, and each has to complete there 5 offers as well.
So, yes I have read about people actually receiving there free stuff...AFTER they go through the lengthy process of cokpleting everything. Most of the stuff you have to pay shipping on, or there is some kind of small fee. If you're looking at getting a FREE* laptop, it will probably end up costing you ~$200 depending on what "offers" you pick.
Before you venture into any offer, research the hel out of it. You may end up getting a $2100 laptop for a mere few hundreds bucks. OR you may spend $200 and get absolutely nothing due to a technicality or time restriction...or anything really. It's risky at any rate.