Personally I think it is much more ethical (and probably easier) to just go to the Manage My Kindle page on Amazon.com, change your address to a Pizza Hut in Boise Idaho and buy the book than it is for Internet acquaintances to be stripping DRM and trading books back and forth. I know that Amazon might put a stop on you eventually but really - if you're buying the book you are buying the book as far as I'm concerned.
I mean, I think a really high percentage of users here probably have Calibre goodies that make what you suggest possible but if we start swapping books around then we are ...... a file sharing site and I know the MR people aren't going to like that.
I understand your frustration though. Its difficult when you are sitting there with money in hand and they don't want to sell to you.