Allofmp3 lost is credit card processing abilities yet they provide a couple options around this, such as purchasing gift certificates or pre-paid cards from a 3rd party. It’s a little of a hassle but it works. Digital Music Weblog says:

Perhaps Visa’s new slogan should be; It’s everywhere you want to be
(unless where you want to be is paying pennies on the dollar for music
downloaded from a quasi-legal website in a former communist state). AllofMp3
has lost its Visa credit card processing abilities according to Boing
Boing and numerous comments on my write up of yesterday’s press event.
After yesterday’s mysterious press conference and AllofMp3’s defiant
declaration that they are operating legally, today’s bombshell may be a
giant leap towards the end.International Herald Tribune via Boing Boing