Other Abundance groups - or similar
The Abundance Network site lists many of the Abundance and similar groups. See HERE
Some other groups are:
London Orchard Project
If you want to find out about how the Abundance idea started, then take a look at the Abundance Sheffield website (Sheffield is where it all started). It gives lots of great information about starting an Abundance group. You can download the handbook HERE. Also, you can join the Abundance Yahoo group for the latest information on what is happening in other Abundance groups.