Well, I'm 29 and I just moved to London from America, and I don't
really know a soul.  I'd like to get to know more people, but from
what I've seen, there's limited selection of venues.  There's always
the pubs and clubs, but it's pretty tough on your own (well, for me
anyway).  I'm looking for more laid back activities that actually
involve talking to people.  Okay, I suppose I should be specific about
my question:

- What are a handful of public activities (with contact info!) that I
could join in the London (preferably Camden) area?  Bonus points for
specifically
  - volunteer theatre work
  - bartending classes
  - complete beginners soccer (or as they call it, football :)
but any activities with fun people will do.

Thanks!

For volunteering in Camden, try the Camden Volunteer Bureau
http://www.camdenvb.org.uk/
You will need to register to search the opportunities database; you
can also go to a session at the drop-in centre in Kentish Town. There
will be someone on hand there to assist you with using the database to
find a volunteer opportunity, or book an appointment to come in to see
an advisor who could offer one-to-one assistance with making your
choices and answer any questions you may have.

Many activities are listed at
http://www.camdentown.co.uk/index.htm

I can't see volunteer theatre work -- do you mean what is called in
the UK 'amateur dramatics' -- but would suggest you check your local
library through
http://www.camden.gov.uk/ccm/navigation/leisure/
as Am Dram is often advertised there. 

For football try Camden Council's Sport and Physical Activity Service
tel 7974 4395 or see
http://www.camden.gov.uk/ccm/content/contacts/non-council-contacts/contacts-for-football.en
oe select Sports and Activities from
http://www.camden.gov.uk/ccm/navigation/leisure/

For courses, the local library is again probably the best place to ask
and should have prospectuses for all the local colleges etc, but the
further education colleges in Camden or nearby are:
http://www.hgsi.ac.uk/
http://www.westking.ac.uk/
http://www.marywardcentre.ac.uk/
http://www.wmcollege.ac.uk/

You could also search on www.londoncolleges.com

Westminster-Kingsway college (wmcollege.ac.uk) has evening classes as follows:
WSET Level 2 Intermediate Certificate in Wines and Spirits (10 weeks)
  Intended as vocational training in product knowledge for those
employed in the drinks industry. The course may also be suitable for
people who are not employed within the drinks industry but who have a
lively interest in wine.

and 
WSET Level 3 Advanced Certificate in Wines and Spirits (16 weeks)
  Designed for trade employees who need to advise management, answer
customer queries authoritatively or make informed selections of wines
and spirits in a wide variety of situations. The course may also be
suitable for people not employed in the industry but who wish to learn
more about the subject.
http://www.westking.ac.uk/wkc_website/courses/courseInfo2.asp?sectionID=11
select courses on the pull-down

Owain

This is great! Why didn't you post it as an answer?