iPhone is surely the smartest phone the mobile industry can offer. For those who STILL don't know about it, here's a layman defination: iPhone combines an iPod (portable music player),

a digital camera device and a mobile phone. This device is like a PDA (personal digital assistant) that also includes an Internet browser application. iPhone also work with WiFi networks in addition to conventional networks.

After reviewing several applications, I picked these ones out as they are surely some of the best apps that AppStore (Apple's iPhone app marketplace) has to offer.