Charlotte, my recommednation is:-
a. Take a photograph of a white sheet of paper at about f11. Transfer to your PC and apply auto-levels in PhotoShop or Elements. The dust will stand out on the resulting image.
b. Assuming their is visible dust then use the Giotto Rocket blower to try to blow the dust away (probably to another part of your camera). The point about this blower is that it suck air from the back so does not suck the dust back into the blower.
c. Repeat a. to see if sufficient dust has been removed. This is all I had to do for the first year of my Camera. If still too much dust continue.
d. Use DigiPads and two drops only of eclipse cleaning fluid. Those who had smears probably used too much but it does evapourate. You just wipe the digipad one way then the other as per the instructions supplied with them.
e. Repeat a. and hopefully your sensor will be clean. Once I had to repeat d. but you must use a new pad.
From my experience dust is often removed by the Rocket Blower though the Artic Butterfly is more effective if you have one. However, the problem is that pollen can stick to the sensor which can only be removed with a pad and fluid.
For those who are nervous about sensor cleaning just look at the sensor cleaning demo at the following link:
Strobist: Sensor Cleaning Demo
I am not recommending that you clean your sensor in such circumstances but it does put the issue into perspective i.e. it is no big deal.