The capital white 'F' on blue background browser icon, as used at
fedora.redhat.com,
fedoraproject.org or fedoraforum.de, is a very good
example of a clear and memorable symbol.
Its only drawback is that since it contains the letter F, it doesn't
look so nice anymore when being put next to a logo like Fedora Project
or Fedora Extras, which would make it look like "F Fedora Project".
It's a bit like "N Novell SUSE Linux" would look. Something abstract
like Ubuntu's three people holding hands has an advantage.
Do we have a big (i.e. 80x80 or 100x100) version of that 'F' logo already?