The eminent Dr. Nic Williams has put together a useful generator that makes it a lot easier to construct your own gems. It's an ideal script if you've never put a gem together before, or if you're sick of the repetition involved. Nic tells me that this tool might make its way into the core RubyGems distribution in the future, but it's worth playing with straight away.

Once installed, all you do is run newgem followed by the desired name of your gem, and Nic's generator creates the correct directories and pre-populates several relevant files (for testing, documentation, Rake tasks, etc.). A real time saver.