I don't know exactly how useful this site is, but I'll let you check it out and decide for yourself. Worst Phone Ever is a site that purports to try and track all of the dropped calls being racked up on Apple's devices and AT&T's service. The idea is that you upload your dropped call log file, then they'll flip through it, and add it to the data they've already compiled.
As of this writing, the site has already parsed over 1.5 million calls, and claim that 5.52 percent of them were dropped, costing users over $154,448 (you can see more about how that's all calculated on their FAQ page).
Now, the paranoid in me has to warn you against actually sending them any logfiles -- while the FAQ claims that no "personal or uniquely identifying information" is in the files, they do say they're tying them to your email address, and I find it hard to believe that there aren't at least area codes in there for Apple's information. Their FAQ, again, admits that they're "going to do everything we can" with the data, and I can't really recommend you give them something from your computer under that agreement.
But if nothing else, the site might turn out to be a nice compendium of information on just how many calls AT&T is dropping. If these averages from earlier this year are any indication, it might be just as high as frustrated customers think it is.