I agree with goodlife - anything that will get people talking and foster some community spirit. In our case, it's working parties, but skips, plant swaps, BBQs are all good ideas.
A regular newsletter is a good idea too, to keep everyone in touch with what's going on; and if it can include informal stuff like recipes, so much the better.
And I think it's a good thing to improve the look of the site. If it looks good, people will appreciate it and look after it. Get the grass cut, trim the hedges, clear the litter, clean out the ditches.