We've recently launched http://apcards.ru (in Russian), Ubercart powered shop for greeting cards manufacturer.
That was an interesting project, and I would like to share the story of the project with the community.
Website screenshot: http://sidashin.ru/my_files/apcards/apcards.jpg
Goals
The main website goal was to create a beautiful modern website where it's convenient for customers to quickly buy hundreds of different products (greeting cards) in 2-3 mouse clicks. The typical visitor of the website is greeting cards reseller.
Views vs Catalog
At the very beginning we've moved from native Ubercart catalog to views powered catalog to take advantage of exposed filters for quick product search form. That was a no-brainer, as views provides much more flexible theming and a lot of crucial features.
The problem of multibuy interface was solved with uc_multibuy + some modifications to views template files to make it work with views:
http://pix.am/nn3G.png
jQuery magic
The views powered exposed search was improved by adding some jquery and ajax magic - we've added 'live' search results count calculation at the moment when customer clicks some search checkbox or changes selectbox state:
http://pix.am/HJQO.png
Customers can use "+" and "-" buttons to change the amount of products that will be added to cart.