There's some good ones here:
http://www.nettime.org/
I particularly reccommend SPECTRE, it's got lots of opportunities for exchanges, residencies etc.
Interesting Mailing Lists to get on
Interesting Mailing Lists to get on
Our big brother's got no heart,
when I get my chance I'm going to punch him in the nose, in the nose, in the nose
when I get my chance I'm going to punch him in the nose, in the nose, in the nose