Protoypes

Information about Prototype iDevices:

Gizmodo iPhone4
iPhone4 prototype first reported by Gizmodo. Brian Hogan, a 21-year-old student at the time, admitted to finding the phone at the Gourmet Haus Staudt in Redwood City, California, after it was left behind by an Apple engineer named Gray Powell, and later selling it to Gizmodo. 

Early iPhone4
Prototype Device reported by micgadget.com which notably shows a different image when plugged into iTunes.

San Francisco bar iPhone
Probably an iPhone4S prototype lost in a San Francisco bar first reported by CNET.

US T-Mobile iPhone
This first was reported by BGR.

64GB iPhone
A iPhone4 (GSM) prototype first reported by micgadget.com. Further details on techmento.com.

White Vietnamese iPhone
First reported by tinhte.vn and further discussed on macstories.net.

TD-SCDMA iPhone
iPhone4 prototype first mentioned by mydrivers.com (in chinese).