What language are you writing your app in? If using J2ME, I would suggest checking out J2ME Polish to organize your builds across multiple platforms. There is a

What language are you writing your app in? If using J2ME, I would suggest checking out J2ME Polish to organize your builds across multiple platforms. There is a built in device database that lists most phones along with their supported APIs. While it wont replace eventual real-world testing, it at least allows you to focus in on devices that support the specific APIs, form factors, etc that you need and ignore the ones which you do not. The J2ME Polish GUI libraries are also excellent and work well across different devices.