Synergy Mod for Source games

Last night I downloaded a mod for Half Life 2 called synergy. Basically what it does is it allows you to play Half Life 2, HL2 episode 1, and HL2 Episode 2 cooperatively online with friends. Why blast zombies by yourself when you can have twice as much firepower with a friend? It is also supposed to be able to play other Half Life 2 mods across the internet as well, but I haven't tried this yet. It runs on Steam and you need to have HL2 or other Source engine games to play it. So, if you have Half Life 2 and this sounds like fun to you, go to http://synergymod.net/ and download right away.