Option 1:
Buy a simple router which sits between the two PCs and the internet
connection.
The router usually has a 4-port switch built-in.
Pro:
Router isn't power hungry and PCs operate independently
Con:
System not directly connected to the internet any more (some applications
don't like it, in most cases its more secure so it can be a pro too).
Need to buy a router, which is probably more expensive than a network card.
<not all comments directly related to reply but lumped
together for completeness' sake).
Generally speaking, one can find out what port is being
blocked if an application isn't working, and *most* routers
can have those ports forwarded.
These days a simple 10/100Mb router, sometimes even though
with 802.11b, can be had for about $10-20 after rebate.
This might be the best option but as mentioned previously
it'd be good to confirm the particular router has either
application support as needed or the typical port-forwarding
if not PNP support. It would be even more important to
disable the 802.11b or secure it in such a dense, university
environment.
Option 2:
Equip one PC with two NICs and use NAT (Network Address Translation), such
as Windows 98SE/2000/XP/2003 "Internet Connection Sharing" does.
Pro:
One system directly connected to the Internet. (better for some sharing
applications, however probably less secure)
Con:
One systems needs to be turned on to use the Internet on the other system.
Option 2 is more flexible when you spend a little money on a switch and buy
an extra cable (preferably straight). This is easer when you get a third
system you want to connect.
A derivative of option 2 might be to just buy a Gigabit NIC
now, which doesn't need a _crossover_ cable to connect to
the laptop, then if/when a 3rd system is needed, THEN one
might buy the router or switch. They're now available for
similar price for basic Realtek/Via/etc chipset (last I
bought was $15 delivered) and it can't hurt to have GbE
support present if/when it's ever desirable to implement it.
As for a switch, might as well buy a router instead even if
routing isn't needed, since they're now as cheap as switches
if bought on sale and even if routing isn't used it COULD be
used in the future. Plus it would seem a natural
progression to eventually add a WiFi card to the notebook
and want the wireless feature of the router.