If you are registered, you get access to the members only section, can participate in the buy & sell second hand forum and last but not least you can reserve your preferred username before someone else takes it.
A matter of how one sees. The very best landscape work in my portfolio was shot with a Brooks VeriWide 100 (47mm SuperAngulon lens on 6x10cm format), which had the equivalent of the 12mm end of the 12-24mm. After going digital, my weapon of choice has been the Coopix 8400 with the equivalent of an 18mm component - same angle as the Brooks and the 12-24mm. Super-wide lenses have the feeling of human vision, including some of the peripheral vision. Though challenging to use, the results can be quite epic.
They are also super for environmental portraiture. See the work of Arnold Newman for ex&les. Since perspective is greatly emphasized, the subject must be within the central third of the image to avoid foreshortening. They also let one work very close to the subjects, and thus produce quite intimate studies. Expect to spend a lot of time practicing and learning - specially at the 12mm end.