AT&T (NYSE: T) is offering the Refurbished iPhone 3G 8GB for $79! If you remember, and I’m sure you do, it all started at $499, with the original iPhone. Two years later, the improved model with 3G radio and GPS costs $400 less, and its refurbished version gets you additional $20 off. Enough said. Here’s a link to AT&T’s website with more details…