[ewencp]

For apt repositories, you might be interested in http://www.aptly.info/, especially if you want to host it on S3 as it integrates very well. As others have mentioned reprepo isn't that tough to use either, but moving it to S3 instead of somewhere else basically amounted to using an S3 URI. It also has some other features that might be handy, e.g. versioning/snapshots and serving your repos locally for testing.

In any case, I find the process of actually creating the packages far more arduous than setting up the repo...