Before you give the 5 instructions to modify the boot.ini, I would put in bold letters "Do not attempt this unless you have SP2." Some people might not read the article by Eaton and Tiffany and attempt this process with XP SP1.
Also, you make it sound like it will work for any program, but that's not true. In order for a program to make use of the /3GB switch, it has to have been compiled with the /largeaddressaware (LAA) switch. However, there is a way to modify an .exe file, giving it LAA support, which means it will recognize the /3GB switch. The ugly way is to use a command line editor from Microsoft called editbin.
A much nicer way is to use a program called LaaTiDo. It's a Windows program. You use the program to search for the .exe file to modify. Then you click "check" to see if it has LAA support. If it doesn't, click "Backup" to make a backup of the file. Then click "Enable" to Enable LAA support. You can then click "check" to confirm that the modified file has LAA support.
I can't test it because I only have 1GB on my system.