i used photoshop CS3.
i mostly used the brush tool for the light beams, then i used the smudge tool, stroking the edges of the light beams outward, to give the beams the 'comet' look. what i did with the brush tool though was alter the brush dynamics.
i made it so with a single stroke, the brush dimensions would constantly shrink until a certain point where it stops, thats how i made the comet tails.
then i changed the dynamics of the brush again (leaving the tail effect) and made them appear like many different sized spots,
thats how i did the little sparkle effects that spiral around the comets.
im glad u liked it