Are you sure? The only cert that I know of that gets close is a wildcard SSL cert which is for *.domain.com but NOT for a common subdomain. The point of SSL is there is at least some verification the person they are who they say they are - that would defeat the purpose.
Also the new IE coming out with Vista is apparently going to implement some new SSL cert which is going to make that sort of deal impossible for sure.
John W, CISSP, C|EH
MS Information Security and Assurance ITEagleEye.com - Server Administration and Security Yawig.com - Managed VPS and Dedicated Servers with VIP Service