It’s almost like a pick-your-poison situation. While the iPhone 4 is a beautifully designed piece of consumer electronics and is capable of excellent things, its novel antenna design has proven to be problematic for some users. I mentioned in a few comments that the issue hits lefties (or people that use their phones with their left hands) more than their right-handed counterparts. The Los Angeles Times explained why this is the case:
Apple redesigned the phone so the steel frame around the handset doubles as its antenna. The left side of the frame is used to broadcast a cellular signal; the right side is for other bands, such as Wi-Fi and Bluetooth.
As a result, people who tend to hold their phone in the left hand may be plagued by the signal problems more than those who hold the phone in their right hand.
As a lefty, I’m kind of bummed about the whole thing. I can take solace in the fact that righties making Skype calls through WiFi should have issues too. Ha ha!!!