I'm working furiously on the mutual_credit module for Drupal 7

It will have pluggable currencies. That means Drupal provides the payment forms, to pay anyone on the site, then there's an internal API which sends the transactions to the wallet, or database.
The whole system is pluggable already, but in a few weeks, each currency will have its own controller.
http://drupal.org/project/mutual_credit

That means we'll be able to run bitcoin alongside Ven alongside community currencies all in one drupal portal.

Hi,
I know what you mean about LETS groups, I've been working the last 3 years to serve them.
http://drupal.org/project/mutual_credit
This strategy is starting to pay off.

I do not think that these groups will be interested in bitcoin because:
-it's complicated
-it is far removed from simple mutual credit which many of them don't really understand.
-these groups prefer to operate in plain sight, than to use encryption
-they have no resources for accounting systems

Bitcoin is already a complementary currency. It just needs to find its niche. Probably the niche is close to where it is now, amongst techies and IT workers. I suggest you concentrate on filling this global niche.

However if anyone does want to work on Drupal for local communities, please get in touch.
Matthew