Anti "all" system

Sure, you log in with Steam, but that doesn't mean the website has access to all your games and such, does it?

I am not sure. You would have to look at the STEAM API and see if there is a way to easily read what games people have. Also some people have profiles as private >_>!

of course there is possibilty in Steam API, lol

ther was a "you have n games worth $m in your profile, your account as validated" or something like that, when i registered, so i think there should be a possibility to go through the list.
that's exactly what i asked a couple of days before, so +1 to suggestion.

Implement this once and for all... and also to dismiss giveaways from appearing in your front page for games that you own already. :D

This would be a great implementation!

I agree.

If this isn't implemented for some reason, I think having advanced sorting options would be a good option. It wouldn't stop dicks from entering giveaways for games they already own, but you could have the site automatically filter out games you tell it you already own. If you win a giveaway and mark it as received, it could automatically add it to this list. It could even automatically withdraw your entry if you mark a game as being owned.

Similar to the amazon.com wishlist.

Sounds cool. Sometimes I enter in multiple contests for the same game hoping to get more chances, but if by some bizarre luck of the draw I ended up winning twice for the same game, I'd feel really bad.