Hmm, hotel rooms can be real expensive in Vegas during big trade shows but you can try bidding on rooms via Priceline (I use the permutations algorithm to maximize the # of free rebids) or you could rent a cheapo car (which unfortunately will cost you) and stay further away such as downtown near Fremont Street, places like South Point or http://www.primmvalleyresorts.com/.
I've stayed a Bufflo Bill's (in Primm) before and it's ~45 min - 1 hour drive (because you'll hit traffic in the morning) to get to Bellagio. You can just drive into Bellagio, park there and take the free CES shuttles into the show. I've done this before when I drove to Vegas.
For those who missed the earlier deadline, there's another code that should work for free registration from http://mashbash.eventbrite.com/.
Are you in the CE industry? Register now for CES and receive FREE registration with priority code MASH12, by midnight, on December 1, 2011.
Ugh! I really want to go!