You can buy my work at the following online shops
At Zazzle you can order most of my personal works and my clip art as prints, card, shirts, mugs, mousepads etc.
At Spreadshirt you can a lot of my personal works and clip art as shirts, mugs, clocks, bags and jigsaw puzzles. Note, from a shipping point of view Spreadshirt.net is mainly for Europeans while Spreadshirt.com is for North American customers.
Other online shops
While you are shopping online I recommend you to take a look at the following sites:
Do I need to say more? Probably the biggest online book shop in the world!
A lot of great stuff to buy or look at ("window shopping"?), and you can set up your own shop for free!
The European equivalence to Zazzle, and you can set up up your own shop for free here as well!
Not a shop but online auction, meaning that you bid for the products you want to buy. You can buy about anything you can think about.
The place to buy my favorite graphics software and a lot of other graphics and web applications.
Other useful sites
If you buy things online you often need a secure way of paying (for example at Ebay). One of the most popular is PayPal.