In reply to EricpAndrew:
Reno is a ~3 hour drive, Vegas and LA are about 5 hours and San Fransisco is about 6 hours. All approximate, of course. That said, the drive over from San Fransisco is very scenic...
Best advice is to just hunt about for a bargain. When you've found a good deal, give a travel agent a call and tell them you'll book there and then if then can beat your internet price.
You might also get a deal if you book car hire at the same time. A 4 wheel drive may be worth considering, depending on where you're hoping to visit.