Play this game. Flash Portal.

If you are like me and cannot install Half Life 2 because you do not have internet access at your home you can at least have fun playing flash portal.

http://www.armorgames.com/games/portaltheflashversion_game.html

Quick hint: The first 9 levels are cake (at least in terms of dying). Then your creepy (alien?) captors start to really try and kill you.

Nice flash game.