The best Cart66 e-commerce WordPress themes of 2011
Cart66, the WordPress e-commerce plugin, is gaining popularity among theme designers. Because Cart66 works with any theme, it’s easy to implement a shopping cart on any WordPress website. You simply create your product and place it, via shortcode, on any page or post. Theme designers are taking Cart66 even further by incorporating features like custom post types and a rating system. Here are two themes built specifically for Cart66 which are especially nice.
Boutique
by ElegantThemes
Some of the features of this beautifully designed ecommerce theme by ElegantThemes are:
Unlimited color schemes
Boutique comes with various background textures and the ability to adjust the background color and font colors giving you an unlimited number of possibilities.
User and author ratings
Boutique allows both authors and consumers to rate each product in your collection, giving your visitors a great way to interact with your website and each other.
Dozens of fonts
Boutique comes with various font options, allowing you to adjust the header and body text independently.
Alternate blog layout
In addition to product pages, Boutique also allows you to run a separate, standard blog section that does not include product info.
Automated thumbnail resizing
This theme utilizes timthumb to automatically resize your thumbnail images. Because of this, only one thumbnail images is required per post, despite the various thumbnail sizes used in the theme.
Advertising management
With Boutique you can place 125×125 banner images in your sidebar and 468×60 ads to your post pages with ease. Advertisements are handled from within wp-admin, and can be turned on and off at any time.
Aquisto
by Press75

Inspired by the popular Etsy.com marketplace, the “Acquisto” WordPress ecommerce theme is the first of hopefully several commerce theme solutions by Press75.com.
Clean layout and design
Acquisto incorporates an efficient 3 column layout including two widgetized sidebars (left and right) and then the center column dedicated to your products, post and page content. Acquisto provides all the functionality you need to sell products of virtually any kind (including physical and digital products). Single product pages allow you to add up to 6 product images in a very smooth product gallery, followed by a very clean product description.
Plugin Compatibility
The Acquisto is compatible with the PulleyApp and Quixly commerce solutions. Pulley is a simple way to sell your digital art, music, videos, photography, fonts, eBooks, software, and other downloadable products. Quixly automatically integrates with your PayPal & Google Checkout accounts and makes delivering your files to your customers a snap.


Can you recommend any others?
Here’s a list of more themes for Cart66
http://cart66.com/integration/themes-for-cart66/