This project will enable all your household telephones to do double duty as a handy intercom system. I would tell you where to find out more about it, but an error when I post says I cannot include links.

Whole House Telephone Intercom

system September 14, 2009, 5:06pm 5

Nice project.

I have never used them but sparkfun linked to batchpcb.com in this project post.

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