I have just cleaned my camera with with Sensorswap and Eclipse E2 solution from Photographic Solutions - I had three specks that just could be blown or shaken off the sensor (I have a D300, btw).
If you cant blow them off, i wont hesitate to recommend this approach - if youre careful to follow the (simple) guidelines, you really cant mess up. I had to do three passes, btw, tough little buggers :-)