Opera just released their Mobile Emulator
for free. It emulates their mobile Opera browser on a Windows, Linux or Mac OS X PC, for multiple devices, like the Samsung Galaxy, HTC Wildfire / Desire / Hero / etc, LG Optimus One, Motorola Xoom and numerous others. I just tried it out, and it works great. Quite a simple way to test how your websites will look like on those devices. I think it is a must-have for web developers.
Apparently, there is also a way to make it run with Opera Dragonfly
Anyway, try the Opera Mobile Emulator, it's great. Hm, do I have to create a mobile version of all my websites now? :)