FreeGameDev

And I think I'll be cursed here, but it's just an idea.

You have the knife and the cheese in hand to get more donations for SuperTuxKart.

With a Multiplayer Online server you could make championships
that to enter the participant must donate $ 5.00 to the STK.
these championships could be made weekly.
players who were in the championship in the first, second and third win awards
a maximum of 20 participants would

I would give a part of donations for example
20 participants x $5 = $100
the first 30%
the second 15%
the third 5%
and $ 50 would be for STK

Logically if the STK was in Steam it would be a success so that's what I think

So basically STK would become a gambling game like online poker? No thanks :-/

See above.

I don't think that fits the spirit of the project at all. Paid tournaments for an open source game? I guess that would just attract a crowd of cheaters and wannabe-haxorz, not really what you want to promote the fun and kid-friendly game-play. Online MP will be a giant leap forward once it is fully implemented, but not for gambling.