Okay, I've got my MCI account how I want it with the calling plan I need (International, calling card, no 800 number, etc.), so I don't really want to start jumping to Sprint and back just to try and earn some miles and create aggravation when I get signed up for the wrong plans and get some ridiculous bill for an international phone call ...

Anyway, has anyone ever switched airlines with MCI? Does it require major changes to your account, or can they leave it intact and just change the airline. I'd like to earn a month or two in AA ... then maybe switch to America West to keep that account alive ... then maybe to UA to get a transaction there ... etc.

It seems to me I could make sure to keep all my FF accounts alive (that are associated with MCI) just by switching the airline I'm earning miles with every couple of months.

I just switched my MCI affiliation from CO to AA and UA (have multiple lines) and it is easy to do. Just make sure you do it right after a billing cycle closes to insure proper crediting.