Mame's -listxml output tells if savestate works for that game or not: look at the "stavestate" attribute in the game's "driver" element.
Yet another dumb question - How would I do that?
I ran "Mame" -listxml >xmlfile and got a 26M xml file and opened that in Opera (browser) but it just looked like a list of all the games strung together. . .

I find it easier to just use notepad than IE or firefox if I just want to look at the info as a whole, as the xml is more a database than a formated paper that browsers treat them. I don't have Opera, so can't tell you anything about that, but IE is dog slow. I actually use textpad at home, but notepad
at work, err... works too.

If I want something clearer or repeatable, xslt is a great flexible way to parse the data and build seperate lists. I just downloaded
Krick's xml2info xslt and edit it as needed. (For example, his xml2list_xslt does a better job than xml2list.exe at translating mame's listxml to the old listinfo format.) He has posted other xslt examples over at
mame.net forum, too. I don't really know the transfomation language, but it's so easy I've been able to piece together stuff by just looking at his examples.
