It took a little while for Sony Ericsson to enter the skinny phone market, but now that they have, they’re unleashing some of pretty hot handsets. Unlike other Walkman phones that came before it, the Sony Ericsson W999i goes with a green motif, rather than the usual orange that we’ve come to associate with the popular musicphone line. It’s arguable whether that’s a good thing or a bad thing, but it is nice to see a little change of pace.

You’ll notice that the W999i rocks the same slim sliding form factor as the mid-range W580i (the W999i is 12.5mm thick), but it combines this with the same SureType-like keyboard as the business-oriented M600. In this way, it’s starting to sound like the W999i is trying to be all things to all people. You’ll also find a 2.4-inch color display, 2.0 megapixel camera, and high-speed HSDPA connectivity.

Based on the model number, I’m inclined to come to one of two conclusions: Either this is the last Walkman phone to ever be produced (unlikely) or every other Walkman phone will not have the same level of specs (also unlikely). I guess we get to look forward to the W1000i…