Changing the cursor

you could put your picture in a an absoulute positioned div tag
and use JavaScript to make the div follow the cursor. I'm not sure
if it would obscure the pointer never tried it, have a look at
http://www.dynamicdrive.com/dynamicindex13/index.html they
should have a similar script for you to look at

remember though, this is a new feature for IE and not supported by most older browsers