There are currently a lot of news stories and videos floating around the internet and Youtube about possible reception issues with the iPhone 4 (and display problems - but that's another issue entirely).
The gist of the reception problem is that if you hold the iPhone 4 on the sides (as if you were on a call) the radio reception drops like a rock to minimal or no service. If you hold it by the front and back, it returns to normal. Very odd indeed.
I have an iPhone 4 and while at first I didn't think I had any problems, I watched a couple videos and tried the same method - uh oh, same problem! What to do?! What to do?!
Well let's slow down a bit... is this software or hardware? Many people are instantly looking at Apple's new outside antenna to blame - you know, the one that goes around the outside band of the phone? A fair assumption - your hand is possibly completing some sort of circuit then when you hold it? Don't know.
Anyway, after reading some news sites, I saw one thing that caught my eye... a few people reporting the 3G and 3GS do the same thing. Well... I just happen to have a 3GS (my g/f's, since mine is "restored" already for sale). I took her case off and tested in the same manner in which I saw in the video (and tested on my iPhone 4)... wait a sec, it's doing the same thing!
OK, so my ONE test with a 3GS isn't solid evidence... but I have seen reports of other people seeing the same results. A few comments on Mashable and Engadget (that I've noticed off the top of my head). Not scientific, no... but I think there's more going on here than just the stainless steel band around the iPhone 4.
One thing I will say is that the results with the 3GS were not as severe. With the iPhone 4, you can easily lose all 5 bars (some people even saw "no service" messages). With the 3GS, I usually only lost 3, maybe 4 bars max. So who knows. A known resolution so far is to install one of Apple's available "Bumpers" around the outside. Isn't that convenient.
In a related issue note... those of you seeing the yellowing of the screen on the iPhone 4 can apparently breath a little easier today as it has now come to light that the yellowish tint may just be from one of the adhesives used on the glass that hasn't completely dried/evaporated. Some users are already reporting the discoloration has subsided or completely went away after normal usage. Yay!