Nothing can make it TMO 3G-capable. It just doesn't have the internal hardware.
It also does not have built-in GPS or WiFi.
I had one and gave it up because of the lacking features. Too big a compromise to get that sexy size and form factor. I also found the OS to be particularly laggy. The other thing that I discovered was that that small size meant too small a screen. I went back to my BlackBerry Bold 9000 rather quickly.