After doing a little research on the web I found that the trick is to take a Double-Sided Double-Density floppy, cover the hole in the disk opposite the write-protect hole with tape and then format it as a 720K disk. Sounds easy enough and fortunately it is. The only problem now is that in Windows XP the format command:

c:\> format a: /F:720

Does not work. The only option in XP is to use /F:1.44. I then dug a little deeper and came across this gem, which does the correct formatting:

C:\> format a: /T:80 /N:9

When I get a little more time, I’ll look up exactly what each of these does, but for now suffice it to say, it does the job and I have now turned several perfectly good 1.44MB floppy discs into 720K floppy discs. Who would have ever thought that might be desireable? :-D