It's pretty tough, I just assume any game I've downloaded is PAL, and boot my 1200 into PAL mode (alot easier than it is on a 500, of course.) Occasionally a game doesnt work in either PAL or NTSC for me, at that point I give up on the game.
I've never heard of anything to convert a game from PAL to NTSC, doesn't seem like an easy task.
When you used the software switcher to go into PAL mode, did your screen start rolling vertically and require v-hold adjustment? (Often happens when switching from 60hz to 50hz modes, but not always depending on your monitor.) That's how I always knew I'd switched screenmodes when I was using my 500+ and a CRT. I think some Agnuses just don't do PAL mode, not sure on that though.
