I was looking for an easy way to create an online store on my Blogger website. I found a few shotty Blogger shopping cart themes that resulted in me having to contract a web design company get things working. I don't think Blogger shopping cart themes are a popular enough idea, and using one would probably result in more trouble then it's worth.

Google Checkout BLogger store

I do have some recommendations. Google owns the payment gateway 'Google Checkout' and 'Blogger' so it's no coincidence that Google offers the combination of the two services into a store feature called the Google Checkout Store Gadget. With the 'Google Checkout Store Gadget', you can setup an account on Google Checkout, list product on a Google Docs spreadsheet, then  embed the store code snippet into a Blogger Widget.

Amazon Blogger store

I was also able to embed my Amazon store 'aStore' into my Blogger website using an HTML/Javascript' embed gadget.

I like using the Amazon store the most. Not only will the visitors to your website see your items, but people search on Amazon will see them too.