Hi Mustachians,
There is group on facebook for MMM followers and we have an active membership of FI'ers, including some FI/personal finance bloggers. We have had a few meetups in the last few months, one forthcoming on 16th November and another on 21 December - all in central London.
The group is called "Financial Independence London".
There is also a group called "Frugal and Freegan London" which complements the financial and philosophical content of the FI group, with money saving tips, offers, events etc.
Please look us up and free to join either or both groups.
John.