I may have a 100 GB hard drive in my aging 15-inch MacBook Pro, but with years of photos, many gigs of iTunes and a 30 GB installation of Parallels on my machine, I am feeling the squeeze with less than 5 GB of free disk space on my machine at any one time. My solution is simple - reduce the size of the partition for Windows XP, which I use very infrequently. But so far I haven't found an easy way to do that without completely erasing my hard disk and rebuilding the machine from the ground up - something that wouldn't be a bad idea in general since I haven't ever done that with this computer.
And so I am contemplating a complete rebuild of my machine next Monday, when I have enough time to devote to such a mundane task on a day off from my job. I won't say I am happy with the idea of spending the time on this, but I don't see an easy alternative. Ugh.