1) LED notification light built into the Home button. Makes sense, right? Lock the screen and the Home Button glows green for a message, blue for an email, red for push, etc. (RAINBOW for a call?! Hahaha)
Oh like the Nokia E71 right?! Sweet, I totally forgot about that. Adding colour LED's for specific notifications, not just the speed of "blinking" would be perfect:
RED - double pulse - for iChat notification or corporate email, rapid for live chat
Blue for personal email, rapid for a live chat.
Yellow for low battery.
1. Not a bad idea but it does seem a little tacky.
This is tastefully done on the Nokia E71 and now released E72. very classy like.
I'd like to add how about
Green pulse/blinking for network signal and good battery life, Yellow for low battery life, and Red "breathing" for low battery life.
This way its VERY quick at a quick glance.
customizable colour LED's: Purple, or other colours .... purple for wife's email, a purple circular ring for say IM from the wife (to let you know night out with the boys has gotten to late and to avoid the dog house its time to get your ass home/message back with an airtight reason

. This way you don't have to be embarrased, its discreet.
still would like louder ringtone, stereo speakers and new features in apps that are already there; ie Search within Safari for displayed websites, coverflow for history bookmarks, ability to Clear Cookies/Cache/History WITHOUT removing saved forms/password entries (this to be seperately deleted from the rest).
Man the iPhone 3GS just rocks!