I have to say that I like the concept of the PayPal Plugin. (While in Beta, this was formerly called the PayPal Virtual Debit Card.) This tool allows you to create a one-time or a one-site Debit Card for shopping on-line. The one-site feature is particularly nice because it allows for recurring charges, but still protects from fraud as the charges can come from only one website.
While playing with the beta version of this a few months back, I found that there was no ability to recall the virtual card numbers that had been created. I used a PayPal virtual card order software from a website. When I went to check on the status of my order, the site asked for the last four-digits of my credit card and I could not give it to them without contacting PayPal customer service. Thankfully, PayPal has fixed this in the public release of the PayPal Plugin.
One feature that I feel is still missing from the Paypal Plugin is the ability to apply a limit. While it is nice to be able to shop without exposing my really credit card info, it is a bit tough that I cannot also establish a limit on the charges that can be applied to the virtual card that I have created. This might be the downside of PayPal having a vested interest in the amount that is charged to the card. This "vested interest" being that credit cards fees are charged as a percentage of the sale.
As a whole, I find that the PayPal Plugin is a useful tool. I will be interested to see what they do to improve upon it in the coming months.