When you develop a Flash Lite or J2ME mobile applications, you'll need to create icons for your app. Although many developers think that it's not important, having an icon associated to your application is important and it helps the user to start up your app faster !
According to different model of mobile devices, you'll have to create some custom icons at custom sizes.
During the last mobile project I worked in Comtaste, I created a small note with a list of different size for mobile icons my graphic designer had to create.
The project was developed in J2ME (it was MobyMobile, a client and server service to optimize web contents for reading them on you're mobile devices. It's still in italian, but we're about to release it in english too) but you can use this list of icons for Flash Lite projects as well :
Then also consider the smallest icon size :