wa lao!! all urs not 'good' enough lor!
anyway, i remember 1 time (ndroo & cyan should know this), i was trying to do a double exposure on 1 film. first was double with colourflash plain wall. then 2nd exposure, was anything, go out shoot.
when i was done with the film, i went to develop.....
and..... i got 36 shots of COLOUR WALLS!!!!!!
well, i think the 2nd exposure, i didnt load the film properly, and it didnt get exposed....
BUT 36 COLOUR WALLS!!!! 
u can't imagine how much time it took to do this...