What's interesting in this case is the report doesn't come from an end user. Instead, it comes from an airline, which we assume more people will tend to believe since the airline itself won't be accused of looking for quick buck from Apple.
According to the report from Regional Express (Rex), which is Australia’s largest independent regional airline, shortly after landing (and thankfully, it was AFTER landing), a passenger's iPhone 4 began "emitting a significant amount of dense smoke" as well as glowing red. A flight attendant extinguished the fire; no passengers or crew were injured.
The iPhone 4 in question is pictured above, via an image in Rex's press release.
claimed he was injured by an exploding Droid 2.
And all this time we thought most people thought the iPhone 4 was "cool." Alternatively, the iPhone has been called "hot." In this case, it was actually a little "too hot."