This tutorial will suggest to you which offers to do at YourPS34Free.com. This enables you get get a Free PS3. The offers I suggest are easily canceled via phone or email and have trials lasting at least one week. They all cost $1.95 or less and take Mastercard, which means you can generate "virtual" cards via the Paypal plug-in. These one-time use cards, which take the money from your paypal balance or your bank account if the paypal balance is short, protect you against unauthorized charges.
The offers I suggest in the tutorial are "Amazing Web Store" (a week-long trial costing $1.95), sign up and if you don't like it cancel the offer via phone or email 4 days after you sign up.
Another real easy offer to do is "Consumer Direct". Its a credit-score company who's offer can be canceled via their website (after you sign-in to your account) or via phone. If you decide not to keep this offer cancel it on the 20th day of the trial.
The other offer I'd recommend is "eAuction Tutor" its a two-week trial costing $1.95 and can be canceled by phone or email. This offer is should be canceled on the 7th day to avoid charges if you do not wish to continue after your trial is over.