Hmmm, a post seems to have been deleted. Well, I might as well take the opportunity to put the finish on my contribution to this thread...
Just thought I'd add to this to explain some issues I've had, and how I've fixed them.
Not long before I started using this memory tweak, I had started using
Mz CPU Accelerator to manage the priorities of my running apps. You can also use the app to assign processor affinity for programs, but in my experience that degraded performance and caused some stability issues.
I had put my mouse and keyboard software on realtime priority and my active Window apps on high priority, but found that while it seem to improve performance in game it actually caused issues with input lag in my chat client and browser. So I have reduced my mouse and keyboards software process priority to high, and disabled the ATI Hotkey Polling service, which in my opinion should have been uninstalled when I removed the Catalyst Control Center software - but more on that to come. This seems to have fixed the input lag problems and improved performance significantly.
I put many other processes that didn't require high priority on low and lowest priority. I had raised chat from lowest to low priority and between that and switching the priority of active window appications and the keyboard and mouse software. I'm not sure I have completely cured the keyboard input lag issue in Firefox and the Miranda chat client, but time will tell. For now it is behaving itself.
I was also experiencing some odd behaviour in terms of my display, for example at one point after a game with a program size over 2GB I was unable to change screen resolutions. I uninstalled the ATI Catalyst Control Center, seeing as it was redundant, I use
ATI Tray Tools which provides all the same functionality, and much more, but is much cleaner and less bloated. Just make sure you use the latest beta for ATT, which you can download from the forums, as the latest release version is very much out of date.
I then found
a simple method for cleaning ram (yes I got this from one of those evil blogs

). It is actually involves running the same utility to perform memory maintenance that Win XP will use periodically.
What I find funny is that someone who has taken one of those Microsoft certification courses submitted comments to the effect that XP's memory management is phenomenal and using this functionality actually made things worse. Which of course begs the question, if it makes things worse, and XP's memory management is so perfect, why does XP make use of this functionality on it's own once every three days? This poster also claims that this process can take up to fifteen minutes. I have never had it take more than a few seconds to complete.
To make a long story a bit longer, I now use this method to clean my ram every time after I run a program that requires a very large amount of ram, and I am no longer experiencing any of the minor issues I was before, which would require a reboot to fix. Now whether the improvements are a result of using this method, or whether they are a result of the other changes I have made, I can't be sure, but I do know it isn't causing any problems.
I should add that in most cases you should be extremely wary of apps that claim to optimize memory. At best they tend to be useless, and they are often used as a vehicle for adware and other forms of malware. What is different about this particular method is that it uses functionality included with Windows XP. It simply gives you control over that functionality, which of course is something we know that Microsoft generally finds distasteful...
I have finally settled on a program size cap of 2.5GB. This leaves 750GB for Windows to work with, and that seems to be a good number. I should also add that I am able to run huge map games of Fall Further, with 46 leaders in the game, with very few issues, although I have yet to get to a very late game scenario with one of these where the demands on memory would be at their peak.