As I write this post, I am connected to the Net using my Nokia 6233. The Nokia 6233 has both Bluetooth as well as GPRS packet data connectivity. It's not very fast, in fact, it's about as slow as a dial-up modem connection, but in a pinch, it should get those very urgent emails in and out. (Update: a 3G connection is relatively fast, but in cases where there's no 3G, the phone reverts back to a regular connection, hence the slow speed.)
Of course, it wasn't easy getting to this point. Initially I relied on a couple of other web sites -- a blog entry from Lynch Consulting and fellow Filipino Ubuntu user Dexter -- for advice. They were helpful to a point but after several failed attempts at trial-and-error, I called in the big guns. Props to Ubuntu wunderkind Zak Elep for his invaluable assistance.
I've broken down the steps into the following major sections:
1. Pairing the cellphone with Ubuntu via Bluetooth.
2. Setting up communications with the Bluetooth device
3. Setting up PPP to use the Bluetooth connection
Also take a look at the helpful Bluetooth dial-up tutorial at the Ubuntu community documentation.