Sifter now offers file uploading. We would have loved to have this in there from day one, but we're big believers in iteration. While this is the last major feature release planned before launch, it's just the tip of the...
http://nextupdate.com/blog/archives/2008/11/file-uploading-for-sifter/We'll only send emails for significant product announcements, and those happen every couple of months at most. Of course, we won't give away or sell your e-mail address either.