For Ubuntu there is this convenient PPA service available where you can get your own package repository.
You can put there source packages which are under an open source license, e.g. development snapshots of your software.
(The server takes care of creating the right binary package and signs it with the repository key.)
Users then only need to add the repository address with one command and can install the packages via apt-get.
Since I am looking into Fedora - is there is something like this available for Fedora packages?
If yes, what architectures/distribution versions are supported? How much space is available?
What is the way to publish packages for multiple rpm distributions via such a service (e.g. current Fedora version and RHEL)?