The NCSA httpd 0.4 release in 1993 announced support for Group Annotations, which was basically this. So all of you "I had this idea four years ago" people need to get in line behind Marc Andreesen, who had this idea, dear god, 16 years ago.
It never really took off--I think even though httpd supported annotations, I don't think Mosaic itself ever really did.
Install VirtualPC on the 64-bit OS, and then install a spare copy of 32-bit XP into a virtual machine. Install the Cisco VPN software on that. Works like a charm, and I kind of like the fact that I've got another firewall between my home machine and the company network.