Sony Ericsson’s quad-band S500i slider is available for free on operator contract. Among its selling points are its sidelights and ever changing themes. In the phone settings you can choose between themes which change as the seasons do, or as day turns into night.
Personally, I’m not sure about some of the themes. Driving rain falling on a tree which has lost many of its leaves for an autumn theme is hardly likely to be very inspirational to owners of this phone, and anyway, automatic theme changing with the seasons seems a bit, well, long term. But the day/night theme is actually quite fun and I do have a bit of a soft spot for animated themes in general. As to the sidelights. Well, these amount to illuminated lights on the left and right edges of the phone, which can be set to glow in different colours depending on what is happening.
Sony Ericsson S500i - TrustedReviews