Rubio and Crist are running for the seat currently occupied by former Crist Chief of Staff George LeMieux after being appointed when Mel Martinez retired.
McCollum is running for Governor not Senate.
Bill Nelson is not up for election until 2012 at which time we have every intention of throwing him out on his rear-end.
US Senate Candidates can be found here http://election.dos.state.fl.us/candidate/canlist.asp
Bill McCollum for Governor, here http://www.billmccollum.com/
Thanks for the correction.