Re: Alien Invasion
I'm actually running an Invasion campaign for my group right now. It's extradimensional, not alien, but I'm sure some of the ideas will translate. We've had a lot of fun with it, though as a GM, it has been a lot of work, too. But it's been well worth it.
If you're interested, our group has a Wiki site that we keep campaign notes and such on. Feel free to take a look at the page for my Invasion campaign: The Invasion Campaign Home Page
There are links to the characters involved, as well as a lot of background information. Feel free to use anything you might find helpful.