www.ancientlab.com can show your PC screen to multiple people at the same time. All that is required is for you to connect your PC to a public IP address and allow your friends to enter your IP address into their web browser. When they enter default username as "guest" and password "guest", they will just need to download and install a player, afterwhich, they can click join meeting to see your screen. It supports 1440 x 1024 VGA resolution.

Public IP can be in DMZ or NAT if you are on wireless or private LAN.