We have been on a couple of rides with the local tandem club where we were the only couple without an intercom system. On one stretch of road with especially heavy traffic, I could see why; we couldn't hear each other at all. Also, many times when I have called out "bump" or "coast" I'm not show that my stoker heard me; so I'm looking into getting one and would like to know others' experiences with them. I'm thinking that clear communications is a critical safety issue.
There seems to be three intercoms specifically marketed to tandemists: a wired one called Tandem-Talk and another wired one called Tandem-Com (through PrecisionTandems.com), and a wireless one sold by PrecisionTandems.com that they call Tandem-Com 2.4 full duplex wireless which is actually a re-branded Eartec Simultalk 24G Wireless (http://eartec.com/Wireless%20Wired/24g.html). I am definitely leaning (95%) toward a wireless one. Could anyone comment on their experiences with any of these?