Has anyone been able to add tethering to their AT&T data plan and keep unlimited data? I've been using Cydia's MyWi pretty much since it was created, but when I got the iPhone 4 I tried to do the right thing by adding the AT&T tethering. When I called AT&T to do this, they told me I could only do it if I switched to the limited 2GB/mo data plan. This seems a little counter intuitive... add tethering and decrease my monthly data allotment. No thank you.