How not to run a contest:

To promote the Beijing Olympics, run a contest offering 10 trips to the Olympics, 5 to Chinese residents, 5 to families elsewhere in the world.

Pare down to the top 50 vote getting families. A friend of mine is in the top 50, so I've heard this first hand. Rather than letting only 1 vote come in per IP address, limit it to 1 vote per minute, resulting in a flood of nonstop voting. After complaints, start round two.

Don't announce the start date for the second and final round. Have an easily hacked captcha, allowing some technically adept families to have 20,000 votes by the end of the first day. When complaints flood in, send a note to all competitors (CC them, instead of BCC'ing them), and tell them that the new rules are that some portion of the results will be their stories that they post, but that votes will also count. Leave all competitors in a state of confusion, wondering how the contest actually works.

Should you want to vote after all that, go here.