phone #s of supercomp centers

Dear netters,
 I would like to have a listing of all the supercomputer centers
 in the USA; i would also like to have their phone numbers (1-800 numbers).
 Since others would probably like to have this information, please respond
 to the net. Is there a directory of such facilities (including universities
 which have a supercomputer on site)?
 Thank you,
 Wayne Sonnen