I wondered if the domain had been registered and found this slightly pointless bit of viral marketing.
http://www.aperturescience.com
there’s apparently a few other logins, like this one to get a mildly witty questionaire:
Type: Login
Username: Valve (Use whatever you want)
Password: Portal
Type: DIR
Type: Apply
Type: Continue
oo another one..
type login
login:anyname > password: portal. then type the “cakeisalie”
and this here’s apparently the ‘spoiler code’ http://paste.uni.cc/9884 if you’re really bored.