I finally got a DS Lite. Almost got one three years ago. But, it was sold out everywhere at the time. Later, I got a Sony PSP. However, the PSP is too slow to load and get to the game. The DS, with its flash based media format, is much quicker. Just turn it on and the game starts almost instantly. Also, you can just close the case and the game will be suspended. Speed is essential if you have a baby at home to take care of. Other factors were that the PSP battery life is terrible and the PSP is not quite as easy to carry around.
I decided to get the DS Lite instead of the new DSi mostly because of the cost. Emma will be playing with it too, so I don't want to invest more than I need to if there is a possibility of it getting destroyed. So far, I only have My Chinese Coach to learn some Mandarin. Emma likes just seeing the device respond to her touch. She also likes the Sketchpad feature of the game to make scribbles on the screen. Will get Emma some puppy game soon.