I found the best case

[tubaguy63]

I really didn't want to buy a case; however the constant call failures forced me to buy one or return the iphone 4. I tried the speakeasy naked and it was terrible. I bought the griffin reveal, which I loved; however the calls continued to drop like crazy. Out of desipration, I tried the free rubber case from cases.com that I received a little over a week ago and my call dropping reduced significantly! I can finally say that my iphone 4 makes calls better than my 3g did. Now, the case looks terrible, is much thicker than I'd like and has shown a lot of ware in the 4 days that I have been using it, but at least I can use the iphone as a phone!

 

[macpro2000]

As much as the phone looks so good without a case...it's definitely necessary for a multitude of reasons.

 

[Romanesq]

another solution...

I found Best Skins Ever really help with the side moldings. You toss the skins in water lay them on and voila, dropped calls are over.

It's blocking you from making that connection with the antenna.

The phone isn't the problem you are. Try some playtex gloves and you'l be find that way too.

A case combined with the side skins is going to be a good fix. You don't have to do the rubber case. In fact the first soft molded case I had was ineffective on the problem.

I'm going to guess any hard plastic on the sides is going to do fine.