*troy joins in the singing...
Just to add another voice to the choir
I have a "beast" of a notebook computer, with 1GB of RAM, a 2GHz Celeron processor (single core), and it runs just fine. I can multi-task with it for my university course with no problems. I'll have a few Firefox tabs open, a few documents, PDF files, folders, and playing music, and I still don't use more than about 850MB of my 1GB RAM stick max, usually I'm sitting around 650-700MB.
Of course, to achieve this, I have to maintain my system - I don't have hardly anything installed on it - and definitely nothing I don't need. I ensure that I have only the minimal startup processes, and keep my system in good nick by regularly cleaning out temp files, and running a disk defragmenter when it's needed.
Just my comments, hope they're helpful.