I've been google-ing like crazy as of late trying to find a company that made 'cool' or modern looking letterboxes/mailboxes. I was having trouble finding any at first but then stumbled upon these following websites:
http://www.outvogue.com.au/
http://www.dangargroup.com/index2.html
http://www.motherofpearl.com/
http://pierrelerouxdesign.com.au/wb/pages/projects/mailboxes.php
They generally lean towards the 'stainless steel' look so if anyone has any other links or know of companies that do custom designs (in any style) please feel free to post.
Or if anyone has built their own and you have pics of it (and possibly the front of the house, too) I hope you'll share. It'll be interesting to see what people have done to the front of the house and/or letterboxes/mailboxes.