I made a mistake in my previous response. The iPod Touch does not officially support Bluetooth tethering, requiring a jailbreak to enable the functionality. Since jailbreaking is risky and currently in a legal gray area (Apple forbids it; a legal ruling is pending), tethering is not really an option. My apologies for the misinformation.
That said, you can use a laptop/netbook/desktop or WindowsMobile device to create an AdHoc network and connect the iPod Touch to it via WiFi. That means it's not possible in your situation unless that cell phone runs WindowsMobile.
Aside from that, the iPod Touch does support entry of contact details and birthday reminders, with third-party applications that fill in additional functionality.