If you don't have cable, then
SF will be showing the Olympics (but in German)
If you have basic cable, then the following are also showing it: TSR, TSI, Eurosport (in English also), ORF, ARD & ZDF, France 2.
If you have Cablecom Digital or Bluwin TV, then the BBC are showing it in English along with 10s of other countries national stations (not english, of course) available via Digital.
http://en.wikipedia.org/wiki/2008_Summer_Olympics has a list of the broadcasters showing it.
Pat