[dishe]

problem is, ensemble billing system restarts your phone upgrade status every time you swap with their automated system. They consider it like you just bought a new phone each time.

Also, there are many times I want to swap ESN's for an hour or two, then switch back (reminiscent of my gsm days), which the automated online system can't do (has a delay, need to be in front of a pc, etc).

m300's esn can be cloned. I did it. I love it.
I can now go on a hike, leave the expensive mogul in the car and take my expendable m300 with me. Return, turn off m300, boot mogul. Easy as pie.

Setting up the cloned ESN, that's the hard part.
Take a look over at mobile-files.com, that's where to find most of this info.
(there's a thread I participated in for exactly this phone)