Contributed packages and trust problem ?

Dear all,

here is a question on which I'd like to get your opinion. Giuseppe Sacco
contributed today a build of the debian packages for PowerPC
architecture based on our Debian Source packages. As he is a member of
the debian project, I think we can consider him as a trusty person. But
what about other persons that may contribute builds for other
architectures ? Did you faced this "problem" in the past ?
Is everybody ok to upload his files on snake (I vote yes) ?
Another thing I wanted to talk about since days concerns signing of our
packages. Is there something done for the moment ? Shall someone sign
the files ? Shall every packager sign its own package ? I'm currently
looking to what's done in Debian and will give you some feedback on it.

Regards,

Raphaël