Random thoughts...
First, why not coat the outside edge of that frame with a clear dielectric, maybe something like matte polyurethane or Power Support film... Probably adds about $2 per phone, more if frame must be minutely resized to allow for coating...
Second, as an older person, I would never hear Steve Jobs whispering "Don't hold it that way" as a subliminal message, so that is a silly idea...
Third, we are talking about a cell phone here. Unless you are Bruce Willis trying to stop a "Fire Sale" in Die Hard XXI, is any given cell call life or death? Even Bruce had trouble getting a good signal. When my college age kids have cell problems (with their Verizon phones), they call me as if their car is on fire and they need someone to help extinguish the flames..... I figure if a call drops, I call someone back or they will call me back. If I miss a call, it goes to voice mail... If it was a bogus call, I escaped...
Having said all that, I cancelled my 7/2 4g phone, and reordered a 7/20 phone. I will save about $20/month with new data/text plan so that is my price for waiting... Will wait and see today's facts and tone as to whether I cancel again.... I saw two iPhone 4s last weekend and their owners were happy. We couldn't show the death grip phenomenon. Until I cruise around with my 4.0.1 3GS, I won't know, but I suspect I live and work in a cell rich environment, so iPhone 4G owners here are happy...
Use things and value people....