QR is the abbreviation for Quick Response, and was named so because the 2D bar code is meant to be decoded at high speed. It was developed in 1994 by Denso-Wave for automobile parts tracking. Since then the technology has evolved to allow much more. To use them you will have to have a camera phone and an app designed to read the QR codes. Google has pushed this most by allowing android phones the ability to scan the code for apps. Blackberry and iPhone users also have apps that allow them to read the codes. Windows Phone 7 users should have one available soon. Just place a search for QR Code reader in your app store to find one you like.
I already mentioned they are used for URLs. That technique is known as a hard link or real world hyperlink. It allows a user to visit a web page without having to type an address. You might have already seen these hard links for marketing use in magazines or on posters, and even on the back of cereal boxes. More recently they are being adopted by governments for expanding the available information a document, like a building permit, provides. QR codes have added support for much more then visiting web sites though. Now a person can use QR codes as a business card that is saved directly to your contacts , geographic locations, adding calendar events, sending SMS, setting up wireless connections, and plain old text. The possibilities for the technology are growing all the time. I'd love to hear what you have used QR codes for.
If you use a program like Wallpaper Master or Display Fusion you can set you speed dial to the wallpaper image that program makes, so every time you open Opera it will match the current wallpaper you are using.
The long way to do this is to open the file you want to be your wallpaper and save it as a generic name (Wallpaper.jpg might be good). You now have two copies of the image. Set your desktop to use the generically named image and do the same for your speed dial. Each time you want the wallpaper changed just open the new image you want to use and save as the generically named image. Hope this works for you guys.