Hooray! Your Linux box just got slightly more awesome with the addition of Portal to Steam’s Ubuntu-friendly collection, if you’re in the beta. Portal is Steamplay compatible so if you, like practically everyone else on Steam, already own a copy you may be able to just go ahead and install it without coughing up USD$9.99 for it.
In less substantiated but maybe more exciting news, sequel Portal 2 has been spotted haunting some parts of the Steam Linux store, as spotted by Gearburn. We haven’t seen it ourselves, unfortunately, but even if it’s complete moonshine you can probably expect it to be true eventually, as Valve seems hellbent on getting every Source engine game running on the alternate OS.