Have you ever seen people selling links to free stuff on ebay and wandered how it actually works ?
If you have, they work in the manner of a pyramid scheme. You visit a free HDTV website, register with them, select your desired free LCD HDTV(e.g a Philips 37PF5521D 37"). One you have completed the trial, you then refer other people to sign up and complete a free trial themselves. When the other people have completed the free trial you then get given your 37" HDTV LCD absolutely free .
So whom actually pays for it ?
Well the company offering the free trial pays the referral free console company a fee, based on the assumption that a certain percentage of people will forget to cancel their free trial (or like the trial enough they want to continue to be fee paying members of the service). With all the fees generated from you and the people you have referred they have enough to pay for your shiny new 32" LCD HDTV and make a profit themselves. So its perfectly legitimate and it actually does work.
So where can I sign up and start referring people ?
One of the best and most established free LCD HDTV websites can be found here http://HDTVGrab.com/index.php?referral=8507