PC Week's method to load OS/2,  Windows, and NT on one machine. The process 
involves using OS/2's dual boot and NT's OS Loader.

1.	Partition a large (500 + M-byte) hard drive using DOS or NT, into at
least three partitions, with the first being at least 200M bytes.
2.	Format the first partition using DOS and install DOS and Windows.
3.	Install Windows NT on the first partition. Install it in a new 
directory called "winnt" --don't let the installation program install over 
Windows.
4.	When the PC reboots, users should get a choice of booting Windows NT
or DOS. Choose Windows NT the first time.
5.	Use NT's format command to format the second partition as HPFS 
(format d:/fs:hpfs) and the third partition as NTFS (format e:/fs:ntfs).
6.	Shut down and let Windows NT start up a second time. During this
boot, the third partition will be changed from FAT to NTFS automatically.
7.	Shut down and reboot. When the NT boot menu appears, choose DOS 
(it will usually be the second choice).
8.	Reboot the system onto the OS/2 boot disk. Install OS/2 on the first
partition. Let it reboot and finish whatever other configuration is necessary.
9.	Reboot to DOS by changing to the OS/2 directory and typing a 
"boot/dos" command. This should cause NT's boot menu to appear when the 
PC reboots.
10.	To reboot OS/2, choose DOS from the NT boot menu and remove a 
command in AUTOEXEC.BAT file that will look something like 
"C:\WINNT\SYSTEM32\SHARE.EXE."
11.	Reboot to DOS again, change to the OS/2 directory and type 
"boot/os2."

I have not tried this personally as I don't have my copy of NT yet, but 
if PC-Week says it works, then it most likely will ... so have fun ... 
you're on your own.