Is that Real Memory or Virtual Memory? Mine only uses about 70MB of Real Memory, which I think is fair enough. I'm just literally playing music with no visualisers or anything fancy. I forget how much iTunes 6.0 used...
even on my decent spec MBP (2.0ghz, 2gig ram) iTunes 7 can be a slug. esp when firing up some of my music videos, and going from windowed to full screen and back.. what a dog!
When I have iTunes 7.0.1 minimized it uses 123 MB real memory, 500 MB virtual. When I scroll through the album covers it spikes to using 360 MB of real memory, but it goes back down right away.