Personally I'd say Flash was better since you can also learn animation and game making (probably not great for iPhone though) as you go along. You don't have to animate of course, but it's easily available and simple to get into.
But You guys know that Photoshop and Flash and Illustrator ARE quite expensive, right ? I can recommend Inkscape for vector art, GIMP for anything unpaletted, and Pixen, Grafx 2 for anything paletted.Flash indeed can be used for low end systems like the iPhone.But I am actualy a bit tired of that fancy Flash look.Pixel art can be much more detailed.
