Catastrophic Wi-Fi iPhone Fail

My trusty iPhone 4S has lost its mind - it's like it's had a lobotomy. 

After months of grumbling about Wi-Fi quality, it finally dawned that the only time there was an issue, it was with the iPhone. Not the computer. Not the iPad. The iPhone. 

The Apple Genius Bar folks say that it's a hardware thing, that for some "unknown reason", a wire is loose. And since the phone is past warranty, but not yet eligible for a (subsidized) upgrade, I'm stuck. With a 4G, non-Wi-Fi phone. 

The little switch isn't even working.