For most of 2009, I've been happily using my T-Mobile VPN service on my new phone, however as of this month T-Mobile has decided to BLOCK my device from their end based solely on the manufacturer of the unit, UNLESS I pay another $25 a month on top of the $20/month I'm already paying for Internet access. I think a 125% increase in my Internet access cost is absolutely ridiculous. Nothing has changed except they decided that if you own a G1 you must be dumb enough to pay more than double for your Internet.
I've just confirmed with technical support that T-Mobile has decided that ONLY if you have a G1 (or a Dev1 in my case), you MUST pay for the dedicated $25/month plan for JUST that device (in addition to your existing data plan that your *other* devices use). I already pay for a data plan that I use between my pcmcia adapter, my Motorola phones (Z8 and V3) and (until now) my G1. As a developer, having Internet access is more or less a requirement, and being able to connect to the Internet while mobile has become a natural extension of my work week.
T-Mobile's own documentation encourages you to use VPNs to protect your data, but if you get their service designed to support VPNs, you may one day be screwed by them when they decide that they didn't mean on *that* device, only on the others.
This is total bullshit by T-Mobile. I've been a loyal and happy customer of theirs for many years and to suddenly screw me like this is ridiculous. Please take your collective heads out of your asses and realize that it's customers like myself that drive dozens of new customers your way each year as WE are the ones consulted by friends and family as to what carrier and product to purchase.