Like many people, I'm having trouble finding an iPhone 4 for purchase in my area. Right now, I'm using an advanced Twitter search to monitor tweets in my area, looking for people celebrating the purchases of their new iPhones, and I'm calling local personal electronics stores after they receive their shipments.
Are there any applications (web or Mac) that could assist me in my search? Feel free to include applications that weren't designed for this purpose. I'm looking for an iPhone 4, but software that helps with this search could help others looking for hardware at other times also.