> If you would like to place a button/menu item under the 
> Tools section in Internet Explorer, then copy/paste the 
> following and save it as a *.REG file. Assumptions, you 
> have Win98SE and have IE6.0 SP1, from what I have found 
the 
> last number can be changed in increments of 1 for each 
> tool/website you want a button for

Thanks for the hint, which also works for Windows 2000.
This key can be random, actually (like a md5 checksum of 
any string such as the full path name)

I played with IE registry keys some time ago, and the only 
problem I had was that you couldn't apparently specify the 
current site URL in the program to be launched (which would 
be greatly useful, instead of having to drag&drop the url)