Below are four premium online contests with grand prizes of a car/SUV, $25k in gas, 2009 Ford Mustang and$100k. Entries can be made ever day. Before posting this, I traced each online entry form back to the parent site to ensure the contests were not an effort to capture your info from a less that reputable source. No guarantees that your info won't be shared with "marketing partners" of the companies offering the prizes.
(1.) Fuse TV (Music TV): Kia keys to the ride sweepstake for either a Kia Spectra or Sportage. Max one entry per household, per day. Sweepstakes valid only for continental U.S. (48 states). Entry period ends 1159pm EST on Sept 30th. Wiki's summary of what Fuse TV.
(2.) Progressive Insurance $25k gasoline giveaway. One entry per day, per household up till 12/31/2008. Three grand prizes of $25k gasoline awarded.
(3.) Better Homes and Gardens $100k Grand Prize Sweepstakes. You don't have to list your phone number on the registration form! Contest thru Feb 15th, 2009, One entry per day, valid on 50 states.
I entered into all of the above sweepstakes and will likely enter again in subsequent days as I remember.