Not all of that is good advice, although most of it is.

First of all, defrag your hard drive BEFORE you change your virtual memory file, and after. Sometimes it works best if you defrag more than once, regardless of what windows recommends. Especially if you are running on Win2k/XP.
Second, 150 is too small a swap file for many folks but it depends on your ammount of RAM. I'd go with 200 if you have 256 megs of RAM. Bump it up to more if you need to. I think it was Tribes 2 that forced me to bump mine up to 300.
Third, set your minimum and maximum swap file size to the SAME number. You DO NOT want windows to expand the file because it will fragment it when it does so and that's bad.
Fourth, that's not a reasonable rule of thumb for AGP apeture size. Anything over 128 is a waste of time, and I'd leave it at 64 megs maximum. No way are you going to need more than that for storing textures in system RAM. Not that you are likely to do that anyway. Test if you like, but don't go setting it to 256 meg of RAM (if you have 512), that's silly.
I don't mean to be negative Bizman, there is lots of good advice in there too! Thanks for posting it.