Umm...turn to the lowest brightness setting, possibly turn it up? Any product you buy to make playing out in the sun easier is going to be nothing but a cheap waste of money.
the lowest brightness setting usually helps, and i do recommend a baseball cap also. it will shade the screens as you play. ^_^
If playing in a bright area (as the sun), this will be the best way. I've had this problem with my DSi but shading the screen didn't really help me. They only were made less quality. I use the lowest brightness when it's REALLY dark. The highest when it is light. Post Merge: [time]1279310820[/time] Also an option.
Wtf? The brightest settings fight off glare. Not the lowest. You could always just build yourself a tarp.
You could attach an oversized collapsable umbrella to your NDS system. That way you can shade the sun from your eyes and prevent glare from the screens. miros