http://www.getinstantfocus.com
It's been an incredible learning experience in terms of building an ecommerce business from the ground up and putting all of the pieces together.
Plus I got to code a custom CRM for the backend because I couldn't find anything to fit my needs.
But I'm running into the serious limitations of having a physical product business-inventory, shipping, returns, phone support, etc. For example, due to various regulatory and logistical issues I can only sell to the United States, which severely limits my market size...I've had to turn away more than a few Canadians...so I'll be jumping into the SaaS startup world soon.
ECommerce is a LOT of work- for anyone choosing between selling a physical product or software, unless you have an awesome idea I would recommend software- a lot of the issues traditional stores face are automatically taken care of in a webapp.