I'm from Tetalab, a hackerspace in Toulouse, France, and we still use the minitel for some hacks with arduino:

http://www.tetalab.org/images/tetalab/MSM.jpg

It's a neat interface, everybody here in France remember it from the 80's, and it quite easy to hack it.

We should soon release an arduino lib for eveybody to hack it, but it'll be quite hard to find a minitel if you're not in France (nobody use it anymore, it's quite easy to find second-hand, but surely heavy to ship...)