This is a little off topic, but I thought I'd ask here. We're
implementing a microtransaction system for Kongregate that would allow
game developers to charge for virtual items in their games. We're
looking for gateways that will securely store credit card data so we
can let users do 1-click style purchases without having to worry about
storing cards ourselves.

I've seen Authorize.net CIM, Braintree, and TrustCommerce Vault
discussed here. Recommendations? Horror stories?

I've gotten pricing from Authorize and Braintree and it looks pretty
close. TrustCommerce hasn't answered yet.

Thanks,
  Jim Greer

I recommend Braintree... it's always a pleasure working with them.  My blog
post on them is here:

http://railskits.com/blog/2008/05/using-braintree/

--
Benjamin Curtis
http://railskits.com/ - Ready-made Rails code
http://catchthebest.com/ - Team-powered recruiting
http://www.bencurtis.com/ - Personal blog