Mark Halperin has a nice cheat sheet on today's numbers. As you can see, we should be getting results from the Republican caucuses in Nevada in the next couple of hours(Update: make that minutes - Romney wins):

Nevada Republican caucuses:

Begin at 9 am PT (12 pm ET)
Straw vote begins at 9:15 - 9:45 am PT (12:15 - 12:45 pm ET)
Precints are asked to conclude at 10:00 am PT (1:00 pm ET)
First results posted 10-10:30 am PT (1-1:30 pm ET)
Results likely known by Nevada Republican Party by 12:30 PT (3:30 ET)

Nevada Democratic caucuses:

Begin at 11:30 am PT (2:30 pm ET).
Preference groups form at 12 pm PT (3:00 pm ET)
Second alignment begins at 12:15 pm PT (3:15 pm ET)
Results start coming into Nevada Democratic Party at 2 pm PT (5 pm ET).

South Carolina GOP primary: polls open statewide from 7 am to 7 pm ET.