After reading varying theories on what caused the signal issues for the iPhone 4 and how Apple can fix it without forcing users to shell out another $30 or hold the phone a certain way, here is perhaps the most interesting theory I've come across along with a rather simple solution that can be applied both individually and globally.
According to a biochemistry PhD who wished to remain unnamed, a likely reason for the antenna issues not showing up in Apple's device testing is the sterile environment in which Apple quality control operates. To be clear, you and I wash our hands when they get dirty. After touching trash, using the bathroom, and sometimes after shaking one too many hands, we take out the soap and water (or maybe hand sanitizer) and scrub. In between washes, however, our body works to produce oils, sweat, and all sorts of fun stuff that doesn't make us dirty per se, but doesn't make us as clean as those working in a sterile environment either.
The biochemist's theory is as follows: "dampness and naturally-occurring salts on the hands of the general populace help them form a better connection with the iPhone 4’s exposed antenna than the clean hands of testers in Apple’s sterile lab environment would have done." So, essentially, this biochemist believes that the lack of testing outside of a lab environment could have lead to Apple neglecting to discover its biggest blunder to date.
There is good news, however. The scientist is not without solution. He believes that adding “'an electrically insulating organic hydrophobic layer atop the bare metal,' such as the thin layer of plastic that encases soda cans," will do the job. He adds that "these plastic coatings can be very very thin films which do not ruin the aesthetics of the device, and would require a minimal change of your production line." These types of plastics can be applied either on a production line as mentioned above, or can be set up for application at Apple stores (for devices already sold) or as at home kits that can be given out to owners.
As I said, it's certainly an interesting theory and you can't complain when the theorist hands you a solution as well. The only thing that's got the hamster wheel in my head still spinning is the following question: Is it really possible that Apple neglected to field test the device enough that they would miss an issue like this? I'm not so sure. What do you think? See the email from the Doctor to Apple, below.
Subject: HowToFix for minimal cost — hydrophobic organic thin film layer
In truth, Apple’s explanation for iPhone 4 signal reception problem is inaccurate at best and disingenuous at worst. iPhone users are in some of the hottest and most humid parts of the country this summer and have salty, damp hands especially at events such as baseball games, barbecues, or other outdoor activities. having bare metal antennae purposely handled will absolutely short the signal. This problem will be difficult to reproduce in Apple’s labs because the engineers are required to wash their hands before touching devices, which also strips off the natural hand electrolytes that are ever-present in the field on a hot day.
Anyway, the solution is not a redesign of the phone, but rather an electrically insulating organic hydrophobic layer atop the bare metal. a variety of plastics will work, such as polyethers, polystyrenes, or nylons. you could even use the plastic labels ever-present on aluminum soda cans, which likewise have an electrically insulating effect when holding said cans. these plastic coatings can be very very thin films which do not ruin the aesthetics of the device, and would require a minimal change of your production line. More importantly, this coating in no way affects the ability to recycle the aluminum — the organic thin film layer will burn away cleanly during the aluminum remelt process. Phones that have already shipped could easily be coated with this new layer at any Apple retail store or with a simple kit you could send to your customers.
In summary, this is a problem of electrochemistry, and certainly NOT a problem of software design, nor one that can possibly be solved by a software update.
Apple needs to hire some chemists.