Yup... as an extension:
What memory is in essence (physical memory that is) is a temporary storage place. It's where commonly used algorithms, programs, etc. are stored because the computer is using them frequently. That being said, it's faster to access something directly from memory than it is from the harddrive.
Virtual memory can be good or bad. The pagefile, which is where the actual contents of this virtual memory are stored, is usually located in your windows or winnt directory. Now, bullcube is a bit conservative with his. He sets it to 1.5 -- I set mine to twice the amount of my memory. I wouldn't do this for a low memory PC, but if you've got a gigabyte like I do -- go for it. I also have a 10,000 RPM hard drive, so the access time is a little bit less.
Here's a real easy tip to speed thins up.
If you're using internet explorer, go into Tools > Internet Options. Click on the settings button for Temporary Internet Items, and reduce the cache size to 1 or 2MB. Windows, by default, sets it to a percentage of your hard drive. I have an 80GB hard drive, so my percentage was about 3GB of my total hard drive space. Folks, this will slow your computer down... make internet surfing terrible, and it can also lead to major major problems with caching and what not. Try it out, should improve things.
That being said, cache is in a sense like virtual memory. Frequently visited webpages are stored there, speeding up internet surfing... theoretically, just keep the space low and your speed will improve.
Back to memory.
If you have a HUGE amount of memory, like 1GB+ -- you can try to go with zero virtual memory. Once your physical memory tops out, no more information can be stored there, so you could end up with some errors... but it's a lot faster that way.
Bottom line is that memory is cheap... but most chipsets don't allow more than a gig or two of memory. Not to mention, higher quantity chips are expensive. Two 512MB chips are cheaper than a 1GB sometimes.
