Haze had a blog post with various new options for the acronym a while back. I don't see an easy way to search his blog for it.

I've always been fascinated (and annoyed) of how it is used, especially by noobs.
MAME can be a proper noun = I'm using MAME to emulate Super Fun Time Mahjong 6.
MAME can be a noun = Look at my awesome MAME I just built. Want to play my MAME? (noob usage)
MAME can be a verb = I'm going to MAME this old cabinet regardless of what the people on KLOV say.
EDIT: Oh and I like it when someone buys an already built cabinet and thinks Hyperspin is MAME.