I live in Brighton too and it would be fun to contribute to something like this. Personally I would prefere people playing music rather than a workshop, although that kind of rules me out as I don't have a laptop and my live playing leaves a lot to be desired
I have heard of others doing workshops but often it has been aimed at children/teenagers and has been funded by arts/government funding, rather charging people to come along (I think).
Whatever it would be cool to do something like this and I would be happy to contribute however I could.