I am seeking advice and words of wisdom from those of you who have walked
this path already.

I have a customer that wants to setup a WSS extranet. Sounds simple so far.

However, they are asking for the following:

1) 400 accounts created

2) 400 sites (1 per account) that only that one account can get into.
The customer would have access to each site, of course.

3) A shared document library that is reflected on each site (or linked)

My question is: how would you handle this?

The customer really wants to make sure the users don't see each other's
sites.

My concern is how quickly/easily it will be to create all those sites.

I have just started looking at the External Collaboration Toolkit and the
Community Kit for SharePont on CodePlex.

Any suggestions on this besides these two options? At this point, I am not
sure how hard/easy it will be to setup distinct sites with the two tools. I
do like the forms-based authentication model because of the ability to
retrieve passwords.

Of course, there is always the old manual method too.

Anyway, any thoughts and suggestions would be GREATLY appreciated.