The other main issue with the phone has been its inability to hold a signal when held in the hand. Some users have it even worse. When some models are held in the left corner, calls are dropped within seconds. The obvious culprit here is the antenna which wraps around the device disguised as stainless steel trim. The internet has been inundated with videos showing similar problems. Many have found that using a rubber case has prevented this problem from occurring. Walt Mossberg, in his review of the handset in the WSJ, wrote that the signal strength indicator problem does not affect its ability to make a call. He says that Apple is aware of the problem and that a software fix is coming. However, this is separate from the issue of the phone losing calls when the left corner is touched. That seems to be a more serious concern and one that Apple needs to address quickly. Unlike other times in the history of the iPhone, the competition has models that can compete with Apple's touchscreen phone.
Apple iPhone 4 Specifications
source: AllThingsDigital, AppleInsiderForum, InsanelyGreatMac