I would second the schools that have already been mentioned, here are some that may not have been, but would also make good choices.

In Britain I would recommend:
The University of Sheffield  (the city is home of Warp Records)

The US :
Renseller Polytech -in New York
San Francisco Conservatoire of Music - has a little electronic department (I am bias because I'm friend's with Alden Jenks)
UC Santa Cruz Electronic Music Studios - I am a slug alumni , offers a minor in electronic music and David Z. sometimes guest lectures.


Though not technically a school there is the center on Haight Ashbury called
Robotspeak that offers some electronic music clinics -more for dance music