The good folks over at App.net have hooked me up with 100 invites to share. Using the link below, up to 100 people can join the free tier of App.net. A standard membership costs $5 a month or $36 a year or you can buy a developer account for $100 a year. If you join, be sure to follow me over on App.net as @katiefloyd and the podcast is @macpowerusers.
Here's the link to activate your free account. If the link doesn't work, it probably means the 100 invites are gone. Check back later as they might be replenished. https://join.app.net/from/katiefloyd