Question: Is there any tool that draws a graphic visualization of a process' memory?

I'd like a graph showing the percentage of pages in physical memory and in the page file.

Answer: 
[Munin](http://munin.projects.linpro.no/) is what you need for Unix-like operating systems. Actually, Munin is great for graphing anything for which you can collect numbers. If you could get one to run a TCP server, it could graph the temperature in your refrigerator.
Using Process Explorer, right-click a process and use the "Properties..." menu. In the "Performance Graph" tab you can see the memory, io and cpu usage of an individual process.