Here's a nice bit of ingenuity. Lifehacker reader Kevin explains how he used a VoIP app (Viber and Line 2 are two nice options) with his iPod's packaging and earbud speakers to create a DIY handset.
After smoothing the edges of the plastic backing and wearing a groove to hold the earbud wire, Kevin used a Dremel to place a hole in the back of the plastic, sealing it with a rubber washer to prevent the hole from slicing the wire. Next, he threaded it through and pulled the wire tight to hold it in place. The result is a functional and decidedly geeky iPod touch phone.
Well done, Kevin! You'll find additional photos here.