Took a series of these the other day/night, down at Albert Park (Melbourne, AU).
I have never photographed a complete sunset before and there were some interesting atmospheric effects on the sun as it disappeared below the smog and horizon lines.

This image was made using:
3 bracketed hand-held shots, +/- 1.5 EV, tone mapped with Photomatix.
The tone mapping didn’t really do much apart from bringing a bit more yellow out in the sun.

Pentax/Sigma
1/90
F 9.5
230 mm