I hear of people saying that freebiejeebies hasn't tracked the completion of their offer, meaning they have to try and complete another one. However, this only happens because they havn't done it properly! I've put together a few tips, that will make sure your offer is tracked, so you can get your free gadget in the post before you know it.
Remember, the time it takes for an offer to go green varies depending on the offer you complete. If you want one that turns green quickly, I recommend Coral bookmakers (remember, by being careful with your bets you're guaranteed to win, see the offers page for details) or Gala Bingo, the last time I completed one of their offers it turned green with 2 minutes of me betting through my £5 deposit, no joke! However, if you're going for the free LoveFilm offer, it'll probably take the duration of your free trial to go green, but you do get a free DVD rental. Ultimately it comes down to your personal taste (and patience to get your free gadget!).
Another very important point is that it's pretty pointless trying to cheat the system by making multiple accounts or refering yourself. They know the IP address where each account is created, and have a "one account per IP" policy. If you try, they'll see what you're doing eventually and block your account, and then there won't be a free iPhone in the post for you!