Flandry, could you let me (us) know how that "random game" entry functions? Should we just press ENTER"?

I'd really like to know because I just figured out a very nice way to get a highly user-customizable set of ROMS onto the N900.

I suggest users of SDLMAME check out RomLister. You can get it here
http://www.waste.org/~winkles/ROMLister/

and I also strongly suggest following the tutorial here
http://wiki.arcadecontrols.com/wiki/RL_tutorials

Of importance is that you get your INI files from the tutorial page, NOT from the links that the RomLister program suggests in its GUI (just trust me on this one...).

The short of it is, RomLister lets you filter out hundreds (thousands!) of ROMS and zero in on the ones you like most - then you can create a BAT file that will copy the ROMS from your MAME folder to any other location, for EASY copying to the N900 - this is a SUPER feature.

Trust me on this, I have been doing ROM management for a long time, and this is the easiest and most productive way I have encountered (after I ironed the bugs out for myself, of course).