I humbly offer my finest pair of unmentionables to the cause of networked underwear. Unfortunately I missed my chance at the ITP (nyu.edu) 2007 winter show a couple weeks ago, but Jaymes Dec and Matthew Fargo presented Jabberjockeys. Described as,

(…) a pair of underwear (one male, one female) which discreetly inform a partner when the other gets aroused. By sensing subtle changes in temperature, moisture and pressure the undergarments detect arousal. The underwear automatically notifies the partner by activating vibrating motors sewn into the fabric of their underwear, thus enabling them to discreetly share their heightened emotions.

Okay, it’s all het-focused and thinks my pussy *emotes* (she certainly feels, but seldom empathizes), but here’s the promising part:

When one becomes aroused, the other’s underwear starts vibrating. This in turn causes arousal in the second party which causes the instigator’s underwear to vibrate, causing a feedback loop of excitement.

Link. (Thanks, Geeked!)