I had some dust on my sensor and bought a Giottos Rocket-Air pump. Luckily for me that the pump was good enough to remove all dust specs off the sensor.
Got the dust whilst changing lens on the beach with a slight breeze. Something to remember when changing lenses is to be aware of the environment your doing this in :angel:
Just don't leave it laying about in the kitchen. I've heard stoies of them being used as turkey baster by accident. Kind of makes your sensor worse next time you go to use it... :o