Howtoforge posted a tutorial about hosting multiple SSL web sites on one IP address with Apache 2.2 and GnuTLS

This tutorial describes how you can host multiple SSL-encrypted web sites (HTTPS) on one IP address with Apache 2.2 and GnuTLS on a Debian Lenny server.

  Hosting Multiple SSL Web Sites On One IP Address With Apache 2.2 And GnuTLS (Debian Lenny)