Manjula,
Actually Buy.com has it. From the looks of it, they have Revolution Card as a credit card option on their drop down. I have to assume that it works like a MC, Visa, AMEX, Discover, etc. Difference being there is no card number just a pin. PayPal would be the closest thing. Google Checkout is also close, but Google Checkout requires it's own separate button, etc, it really doesn't work with a traditional shopping cart. Luckily I was able to do my Google Checkout integration very easily. I think that Americommerce has the most Google Checkout friendly system. I have a support request out for Revolution Card, in addition I also have a call out to them. I placed the call on the 18th, so I assume they are up to their butts in alligators, as far as requests go.
I will keep you posted on what I find out.
Best Regards,
Louis
TackleToyStore.com