Alright, so a lot of hype regarding Portal (http://forum.team17.co.uk/showthread.php?t=29869) has suddenly overwhelmed the internet. So I thought i'd post a link to a game that inspired Portal.

Valve Corporation is releasing a professionally-developed semi-sequel to Narbacular Drop entitled Portal. It is expected to be released Fall 2006, bundled with Half-Life 2: Episode Two, for PC. Some or all of the original Drop team are now employed at Valve.

Here you go!

http://public.planetmirror.com/pub/vgpro/misc/narbacular_drop/narbacular_drop.exe

Yeah, Valve seem to recognize great games ides and immediately buy them.
Even with the whole developing teams.

Just like Team Fortress, Counterstrike and Day of Defeat.

I'd contest day of defeat :p but otherwise yes. It works very well too I'd imagine, especially when they publish themselves.