In terms of cell phone reception, both iPhone and Curve 8310 feature a GSM 850Mhz band which is commonly used by many North American cell phone providers such as Rogers, Fido, AT&T, etc. Thus, the cell phone quality should be about equivalent in both the phones. There does exist a problem of scarcity of available applications for the Curve 8310; however, installing free applications in an iPhone 3G requires jailbreaking it and jailbreaking VOIDS your phone warranty. But Blackberry OS is reaching out in the market and availability of blackberry applications in the long run should not be a problem (atleast in my opinion)

In a nutshell, if I were you, I would buy a Bold for $149 from AT&T with a 2 or 3 yr contract opposed to buying a $200 iPhone 3G and paying high internet data rates. Also, iPhone 3G lacks a few features that you DO get even in low entry cell phones. Features such as Bluetooth file sharing, camera flash, a physical QWERTY keyboard (preferred more by me than the digital iPhone keyboard), and push e-mail (which is what Blackberries are meant for)