I would also like to express my interest in this query.
i just hope the answer isnt to create a mod of portal, once the sdk comes out that is. because that would just be overkill
I'm not even sure we'll be able to do this even if we create a mod, since the Achievements thing is tied into Steam Community.
Ak, hadn't even thought about that. we'll just have to wait and see
I was thinking about this the other day as well.
We may have to wait for the SDK to come out then we MIGHT be able to make them, but they will not show up on our profiles.
Might be possible to make some cheat-achievements, with scripts and global variables, ending in a text message (or even audio, or something that happens in-game) indicating the achievement unlockage.