Gazelle is a site that allows end users to trade in their used electronics and receive cash in return. While not limited to iDevices, whenever an iPhone or iPad is released, the site receives a ton of attention.
[Another service that gets a lot of traffic during such times of electronic replacements is eBay's Instant Sale.]
The contest is simple: first, you have to "like" Gazelle on Facebook. Then, you can enter a contest in which you attempt to predict the release date of the iPhone 5.
Considering there have been numerous rumors about that date, unless we and many others are wrong, that's easy to "predict."
You can enter only once. The contest runs from now until Aug. 20, 2012, at 11:59 p.m. ET.
Only those correctly guessing the release date are entered into the contest.
Also, the rules for the contest say that the value of the gift card is for the iPhone with the lowest amount of data storage. Although the company uses $649 for an example of what someone would win now (equivalent to an unsubsidized 16GB iPhone 4S), it added that the amount could vary depending on how Apple prices things.
What's interesting is that Gazelle says that the drawing for the contest will be on or about Aug. 31, 2012, which - if the current rumored release date is correct - is just a tad bit early.