The answer greatly depends on what all features of the phone or API do you use. In-case if you dont use any special features specific to phones such as alpha transperancy or sounds, this list wil do
Nokia, samsung, Sony Ericsson.
Motorola,
LG, Sharp (Not sure)
The above list depends purely on keycodes. Incase if you develop a midlet based application there is no need for porting...
What I mean is that, Example for nokia, we are going to group the handset of nokia by scrensize, keycode or OS? then Samsung is by which feature? and so on.....
Because i am going to develop game for mobile phones.
we usually develop a game for 176x220 and then port it to other screensizes like 128x128, 128x160, 176x208 and 24x320. Then we port all these builds to each manufacturers.