I have been using dual monitor setup from last 2-3 days and I must say I am quite addicted to the use my extended monitor Samsung 19 inch with my hp tx1000 laptop.
Yesterday, I was googling about how to setup different wallpapers on my laptop monitor and 19 inch extended monitor, I found a free utility called DisplayFusion which can make your multiple monitor experience more better and soothing by adding a separate taskbar on both the monitors attached to your machine and these taskbar will look like windows taskbar.
It will also allow you to set different background on both of the two monitor connected irrespective of which one is primary and which one is secondary.
Most of the features mentioned below comes in the pro version which you have to buy, but you can have different desktop wallpaper and multi monitor taskbar and some other features in the free version of display fusion
Some Key Features Of DisplayFusion
1. Use Different Desktop Wallpaper on each monitor
2. Use a a single wide monitor wallpaper which spans across on all the connected monitors
3. Change the desktop wallpaper on both the monitors using the local images or flickr images
4. You can move different windows from one monitor to another monitor with simple keyboard shortcuts
5. Auto Snap windows to the edge of your monitor
Download Display Fusion to set different desktop wallpaper all the monitors connected to you PC