Big Hairy Installer, despite the unusual name, is actually a flexible installation maker. It allows you to group files together, and create them into a single installation application that will place the files in specific parts on a users Mac. For example, you can have your extensions automatically placed in the user's extensions folder.
Version 2.0 features a new Easy Install option that mimics traditional installers. It uses a very similar file structure, but allows you the luxuries of a one-click installer.