Door Knocker

I most likely won't be going with one of these, but it's nice to know there are some really nice alternatives to the shiny brass Home Depot specials:

• Door Knocker by Reveal Designs - super elegant, mechanical
• Door Knocker by Umbra - the only other well-designed one I've seen

And something similar in nature:

• Doorbells (I like square and round) by Spore - Awesome. Also make the actual bell.