The mobile industry is not very good at publishing specific
information about phone capabilities; which is of use to the mobile
industry. As a developer we need a more complete picture of the type
of compatible phones out there.
The phones we require information on should be sold in the US or
Europe and should contain the manufacture and the model name and any
extra information you feel relevant.
The four types of phones we require information on are(a phone can fit
more than one category):-

Colour Java
Colour Symbian
Phones that can play 3gpp video clips
MMS Enabled Phones

An good extra tip will be available for a large range of manufacturers
and if you can tell us if the phone supports animated GIF and whether
it supports high speed data(like GPRS or Edge)

If you could put this in a spread sheet this would be even more useful.

I feel for you.  We are in the same boat (http://www.mfoundry.com). 
What we have found to be quite useful is an open source project called
WURFL (http://wurfl.sourceforge.net/).

 The WURFL is an XML configuration file which contains information
about capabilities and features of several wireless devices.

The main scope of the file is to collect as much information as we can
about all the existing wireless devices that access WAP pages so that
developers will be able to build better applications and better
services for the users.

This project is open-source and is intended for developers working
with the WAP and Wireless. All the information listed here has been
collected by many different people from many different countries. You
are allowed to use WURFL in any of your applications, free or
commercial. The only thing required is to make any modification to
this file public, following the original spirit and idea of the
creators of this project. This will help WURFL to grow better and
better every day.