Maybe just create a dev group in Google for now and see how things go.

I have a bad memory of google groups blocking a group into which I was a member 
(it was:
http://groups.google.com/group/rakontointeraktiva/ ) for a violation of "term 
of services", but since at the end if was half abandoned, maybe it was just 
spammed and the moderator didn't do anything, I don't know, so why not, I think 
it might be better than the one currently used. 

On the other hand, what I don't like on google groups (in addition to the other 
reason given above), is you can't reply if the thread is too old (around 2 
months, which is not **that** old), and I don't really see the point of it: if 
an user has some inquiries or thoughts, two months later a reply might still be 
relevant.

I'd rather like to see a phpBB forum, or something equivalent.

As long as i know, it is very easy for some stupid person to report a group at 
google and get that group blocked. :( 

If Django, Tornado and Sphinx use google groups, I really think it's ok for 
txt2tags too !

For the devel list : it's a need (no web forum for developers Eric !).
For the user list : a web forum could be fine, but it's more complex to do and 
to admin. If there's volonteer to do the work, why not. But at least a google 
group, sourceforge mailing lists are useless.

Since now we have the txt2tags-dev Google Group, I'm closing this issue, ok? 
Thanks Florent for the idea!