This is cool. One of the criticisms of PayPal has been that although it's great for eBay purchases and has been widening its acceptance, it's still hard to use your PayPal balances to buy stuff at most online stores. But a new PayPal/MasterCard service called PayPal Secured Card will allow you to make purchases online as if you are using a MasterCard, with the purchase price coming out of your paypal account (or from your existing credit card if you just want to use the PayPal product as a way to disguise your "real" credit card number).

From Reuters:

Through a partnership with credit card issuer MasterCard Inc, Secure Card generates a unique MasterCard number each time a PayPal user arrives on an e-commerce sales checkout page that does not otherwise accept its payments.

So you get a one-time-only credit card number while using your PayPal account. There are a lot of happy PayPal-ers today.