It was a while ago but I believe I've used touch on windows, from cygwin. You just need cygwin1.dll in the same folder as touch.exe, and call it from bash.exe.

There are ports which do not require the cygwin emulation layer nor a *nix shell to launched from:

C:\temp>touch foo2.txt

C:\temp>dir foo2.txt
 Il volume nell'unità C non ha etichetta.
 Numero di serie del volume: 0464-729A

 Directory di C:\temp

07/06/2007  21.50                 0 foo2.txt
               1 File              0 byte
               0 Directory   3.396.943.872 byte disponibili
[download]

OTOH, does anybody remember Borland's touch.com?