househacker/tags/intercom http://www.househacker.com/ househacker/tags/intercom Utilize Unused Telephone Lines to Make a Home Intercom System Markus Wandel has created a nice DIY home intercom howto, complete with schematics and usage instructions:

If you can manage it, get two speakerphone-type phones. Leave them in "speakerphone" mode continuously and pound on the keypad to attract the attention of the other end.

Heh. Via Boing Boing.]]> http://www.househacker.com/permanent/Utilize-Unused-Telephone-Lines-to-Make-a-Home-Intercom-System