iPhone 4 proximity sensor, wifi & extra piece?

Replaced my screen... It works visually and touch interface is golden too. I'm super stoked to NOT be using my husband's droid X!

Wifi is non existant. I'm 99% sure I had the little metal clip when I took it apart (I remember it being the first thing to jump off unannounced) but its gone. Does anyone know where to get a replacement or how to fashion a fix? I'd rather not check my email in my laundry room (where the router is located in our home) but I can do it for a while...

The proximity sensor I'm not worrying about until I have to disassemble to actually fix the wifi, but which method is the best; the floppy disk film over the whole thing or the electrical tape blocking?

The extra piece baffles me. I thought this was the metal clip from the wifi problem, but I've yet to find it in pictures anywhere... pic link Where does it go and what does it do?!