This'll work on many handsets, but here are the step-by-step I used on the Nokia 6086. I use the free dial-up service provided by NoCharge. $6/m t-zones is enough to use opera mini and google maps, but I was minimizing my plan and dropped it, since I hardly ever use these, but they can help if on a road trip and you get lost :)
Start in Menu > Settings > Configuration > Personal configuration settings. Then Options > Add New > Access Point.
Account Name: NoCharge CSD Access Point Settings... Data Bearer: GSM data Bearer Settings... Dial-up number: 3604692222 Authentication type: Normal Data call type: Analog Data call speed: Automatic User name: guest Password: password Display terminal window: no
That's all you need to get Opera Mini working, but you can add a Web setting for t-zones as well... Make sure you go back and change Default configuration settings to Personal config. You should also add MMS into your personal configuration since it doesn't seem to fall-back to the other config for items not in your personal configuration, plus you don't want to use your CSD access point to download your picture messages, we'll use their GPRS (which doesn't allow internet connectivity without t-zones plan).
As before, Add new > Picture msg.:
Server address: http://184.108.40.206/servlets/mms Use perferred access point: No Access Point Settings: Proxy: Enabled Proxy address: 220.127.116.11 Proxy port: 8080 Bearer Settings: Packet data access point: wap.voicestream.com Network type: IPv4 Authentication type: Normal User name: [blank] Password: [blank]
Voila, you have dial-up on your phone and your MMS still works. Dial-up is limited to 9600bps at best, but it does the job. Revert to t-zones when needed to use their site. Also, of course this uses your airtime because it is "dial-up". Don't say I didn't warn you.