so quick, thanks guys.
one more thing. i bought a new iBook 12' which comes with a 40GB HD. well once i started it up, i only had 24GBs of free memory. now i know there is going to be some discrepency between what is advertised and how much memory is actually free (definition of what a GB is, OSX takes memory etc.). however, doesnt 16GBs missing seem much?
edit: i wanted to look into system profiler to see exactly what HD is in my iBook (maybe they accidentally put a 30GB in mine), but i cant seem to find my HD in the profiler