I used virtual account numbers a couple of years ago ago on a swedish bank (swedbank, lol). Worked very good. They had both use-only-once (and specified maximum charge), and use-multiple-times (and specified maximum charge).

I used it sometimes for hotels and some other Inet business. But now I don't bother anymore, and just use my usual CC:s. As long as it's a (standard) "secure" ssl-transfer I'm not that worried. And if I was unlucky and got scammed, I would say that swedish banks have a pretty good reputation of giving you your money back.