http://www.laplink.com/products/llgold/overview.asp
Includes a "special" USB cable for this purpose. Of course, why go through
all this trouble if you have LAN ports (most people do). Just get yourself
a $2 ethernet crossover cable (available almost anywhere fine PC products
are sold
, patch the PC over those ports, and "network" to your heart's
content! Even if you have to buy a couple of PCI ethernet cards and some
cable, it would cost far less than Laplink.
So yeah, you can do it, but it's hard to think of the circumstances under
which this is economically justified, there are just too many other better
ways. Heck, I'd probably install some inexpensive USB wireless (802.11b)
adapters between the PCs (run them in ad-hoc mode) before going the Laplink
route.
HTH
Jim