The dust blowing thing worked for me!
Go to an un dusty room, not near any electronic equitment, then blow air on the mirror, then do it on the sensor, then on the inside of the lens.
It took me a good 4 or 5 tries before I got rid of the dust mark on mine (which was rather large, about 100 pixels in diameter...oh whatever i could see it in the viewfinder it was big enough lol) but it ran away in the end
Canon EOS 5DmkII + BG-E6 + Canon EOS 40D + BG-E2N + Canon EOS 33
Canon 17-40 F/4L
USM + Canon 24-70 F/2.8L
USM + Canon 28mm F/1.8 USM + Canon 70-200 F/2.8L
USM IS + Canon 85mm F/1.8 USM
Canon Speedlite 580EX II + Canon Speedlite 540EZ + 2 x Nikon SB-80DX
Cactus V2s Wireless Trigger - 5 x
Cactus V2s Wireless Reciever