or, you know, no encryption at all, and assign a MAC filter. That is the best way to go imho. Your router automatically disregards any packets coming from unknown mac addresses, this is better then any encryption (which can be circumvented)
No compatibility problems.
The DSi Browser would be a whole lot better if it supported flash and extended memory. Every time i browse the web on the DSi i nearly want to throw the thing against the wall.
If you have to extract information from the internet, yes, you can accomplish that with the browser. But comfortably browse the internet? Nope, at least, i can't.
But then again, i never bought the DSi for that reason. I want to play games on it, and maybe some AAC's. For the rest, the console is just not equipped enough to be fair.