If you register a credit card with Anime Chaos, 
they will authorize a certain amount, but you 
won't be charged.  You don't have to pay any 
deposit if you register a CC, and you don't even 
have to use the CC to pay for your wins if you 
don't want to (you can use PayPal or a MO, etc, 
instead).  The details are on the site. :)