The Grip of Death has become a widely-reported issue with the iPhone 4. For those who don't know about it, the Grip of Death is the name given to an issue in which holding the iPhone improperly causes attenuation of the phone's signal.
Unfortunately, left-handed iPhone owners are the ones having the problems, because of the way the phone fits in the left-hand when held.
Apple has said that all phones experience some kind of signal drop when held, but it has become a popular story with the iPhone 4. Whether a bad design choice, or internet hype, the reports of signal drop are true.
However, this isn't limited to the iPhone 4. The above video of what is what the poster calls the "Ericsson Grip of Death." In it, he shows a, TEMS Ericsson K800i test unit being given the "Grip of Death" the result is a severe drop in signal.
He goes on to say that his point isn't that the iPhone shouldn't have a problem, but that it's not alone when it comes to such issues.
Remember that Apple also recently somewhat explained the issue by saying that they botched the way the iPhone 4 calculates its reception. While many say that this is not a fix, it will definitely give users a more accurate representation of their level of signal.