Do a status match to Continental (and quickly since nobody knows when they will stop doing it - check that forum) from AA Plat to CO Plat. Since UA/CO will merge at some point I would just choose that if you want a US based program. There are chase credit cards that will help you out if you want.
I guess M&M would be okay, but I hear the redemption options are not great - I have no real basis to make the last statement - just what it posted around.
Cheers.
http://www.flyertalk.com/forum/conti...h-onepass.html