Blockchain.info wallet: how to reverse SMS and Email payments

[glitch003]

Hi, on the blockchain.info site it says this: "A Copy of the private key is kept in the senders wallet so they can reverse the payment at anytime until claimed."

I sent some bitcoins to people who I'm not sure will claim them, so I'm going to wait a few weeks and then reverse they payment if they haven't claimed it yet.

How do I do that?  Does anyone have experience doing it?  I can't find anything on the blockchain.info site to do it.  It says they're saved to my wallet, so does that mean I have to import the wallet to a bitcoin client to get at those private keys since I can't seem to view them on the blockchain.info site?

Thanks!

[piuk]

Sending by SMS/Email works by generating a new private key, saving that key in your wallet and then mailing a copy of the private key to the recipient. That way both sender and recipient both have full control of the funds until one of them send them elsewhere.

If you look in Archived addresses there should be an address label "Sent Via SMS/Email to XX". If you sweep that address the funds will be reclaimed back into your own wallet.