inviting people to join this group

Well, I coined the concept, but I am not an owner of anything here. It is an open group, so go ahead. Just please, mind the goal of it.

I need to discuss things efficiently. Please regard me as an outside expert. I need to focus on key players and don't have time to read long discussions. I'm happy just talking to you and getting more involved later in person in Greece.

OK! In any case, I mention here some people I could contact in case there is any issue: Brett Scott, Jens Martignoni from Zurich, Giuseppe Littera from Sardex, Chris Cook (UCL), collaborators from the COMPARE project, who are also more or less "new" in this area (Alexandros Kioupkiolis, Aristotle University of Thessaloniki, Paolo Dini, LSE), and Theodoros Karyotis (activist in Thessaloniki involved in Micropolis).

I know brett
I know Jens slightly
I never met Guiseppe
I know Chris slightly
I don't know the others.
Maybe the problem is that I don't know yet what this forum is hoping to achieve. Is this a design and implementation discussion? Are we planning something?
Are we just sharing ideas?

I guess there is no clear goal yet, but we could define one :-)

In my mind, a possible way to frame it could be like a "think tank for Greece" where outside experts like Matthew share their experiences with interested greeks, who provide some local knowledge and context, and all together try to think of a few concrete steps toward a realistic project ... or something like this?

Panayotis is right. I am really happy somebody could phrase it much better than I did.
I will be happy to learn from you, to participate whatever I can and to act as a go-to anarchist if the whole work goes too statist. :-)

A think tank is good, but think tanks don't usually implement solutions.

So, an unusual think tank, then?

Seriously speaking, I have already started looking for supporters. As soon as I get somebody serious, I will bring them here. And yes, I already started arranging some modest funding -- in an unusual way, as usual. :-)

OK but who those supporters are and what that funding demands are serious design considerations, so they need to be stated.
Here's a suggestion.
Make a web site in English and Greek called 'Credit Commons for Greece'
On it, explain why if Greece succeeds in keeping the Euro together, Greece in deflation needs a liquidity tool for business and/or for less formal exchange.
Talk about the solidarity economy initiatives and how they need joining up in order to scale. Read this to help you https://docs.google.com/document/d/1pBk9mBWXssojrIo-gyD0bd1zu3wAZTyQjo9r1IE-Z4U/edit#
Talk about the kinds of partners you are actively seeking to make this a reality.
Talk about the kind of money you might need to roll out a proof of concept, excluding PR
Show awareness of the Varoufakis B Plans and how these plans fit in to that.
Mention the benefits of blockchains and how they enable money systems without centralised trust and the people don't need permission to create money any more.
Mention the international experts and what they have brought to the project already.
Presto!
You have a think tank, an agenda, a project, a philosophy, and a direction. Maybe its time to pull it all together. Before you have the answer, you need the question! We English know this because of Hitchhiker's Guide to the Galaxy!

This is really impressive and perhaps I will be able to set up the website you pictured -- as soon as I find somebody Greek speaking to make it :-) . I will surely start writing up an outline, following your suggestions here and in another thread.