Just disable the 3G data and you're good to go. You don't have to subscribe to anything additional from T-Mo. Unfortunately, the Behold lacks wifi. The G1 has it though.
I always thought you could still get 10GB of data for $24.95(?).
I want to upgrade my cell phone but don't really NEED the internet capability. It would just be a "nice to have" feature. I currently have T-mobile for service and would like to stay with him. However, I keep seeing that the plans are $34.99 just for internet access. What I'd like to know is are these phones (I'm looking at the Samsung Behold or the G1) capable of picking up WIFI where it is offered for free. Or do I have to subscribe to the internet service through T-mobile?