I've just tried this out with TextEdit, and it works just as advertised. Thanks very much for emailing it to me, Greg (tried to email you back, but got blocked by an overzealous spam filter -- repeatedly, despite getting several IP addresses unblocked).

Particularly useful is its accessibility in the 'Save' dialog box (so I can append dates to file names as I save them).

I guess it would be a whole 'nother layer of complexity to get a service to insert the date/time as a live field that updates automatically, as in NeoOffice 2.1?