The gift circle has been self-replicating through word of mouth, gift circle workshops, people going on tour to spread the word, and a number of folks writing about it.
Here is a list of current ongoing gift circles I am aware of (with my rough guesses of when they started):
Fairfax CA 10/09
Ashland OR 10/09
Hollywood (Evolver spore) 11/10
Forest Knolls CA 12/10
Mill Valley (Transition town) CA 12/10
Nevada City NV 12/10
Mt Shasta CA 1/11
Joshua Tree CA 2/11
Point Reyes CA 4/11
There have also been many gift circles that were held once or a few times in many different places – New Haven, Portland Food not Bombs, Santa Barbara coop, San Jose, Earthdance festival, workshops in LA… A number of Transition towns have tried it out – Transition SF, Transition Harrisburg CT, Transition Pittsburg, Transition Albany CA. And a number of Evolver spores have run gift circles.
12/11 update: I have heard of gift circles in Austin, Monroeville, various places in Los Angeles, Cape Town (South Africa), and in Israel (heres a website in Hebrew about gift circles http://maagalmatanot.wordpress.com/ ). Gift circles self-replicate virally, so it isn’t clear how many gift circles are out there. Its possible I have only heard about 10% of the gift circles that exist. For instance I know about the Mt Shasta gift circle, only because a friend of mine stumbled upon a flier on a Mt Shasta Health food store bulletin board about it