This is sort of old news, but I realized I have not written about this before... Tira Wirless has a free version of its modd mobile device database available on the net (there is also for-fee Standard and Enterprise Editions). The database covers quite a nice number of manufacturers and handsets (did not see any major player missing from there, that's for sure...)

You need to register to Tira Go Mobile Community to be able to access the database, which contains information about the devices as well as the Java implementations. The free version lists basic form factor information, Java API support and general Java VM stuff (JAR size, heap, RMS, performance index, etc.)

The for-fee standard edition adds many, many more bits of information: system properties, browser & WAP characteristics, protocol support, Java system event behavior, key codes and other detailed Java API information. It might be worthwhile for Java-developers to check this out...