It seems like a lot of people are having problems using yesterdays tip with Outlook 2003.
Yes, it does work with Outlook 2003. I'm pretty sure it also works with Outlook 2002 and possibly Outlook 2000 (but haven't loaded a machine to verify either yet). It will work with any version that supports Hyperlinks on the toolbar buttons.
Hyperlinks used to be very useful (not that they aren't useful now), before security concerns caused Microsoft to lock Outlook down. You could hyperlink to programs, templates, files, websites… just about anything. While you still can link to anything that has a file path, you'll get a lot more security alerts asking for approval or the button will act "dead" and nothing happens.
The main problem areas with yesterday's tip seems to be with finding the customize dialog and customizing the button.
If you can't see the Views, Toolbars, Customize command you can right click on any toolbar and choose Customize to open the Customize dialog.
You'll need to leave the customize dialog open until you've added the hyperlink (and customized the button, if desired).