kittylester - all of them, if you'd like! Just go to one of those sites and hover your mouse over my sites in the top-right corner. If you click edit while you're there, a pop-up box will give you the option to add more than one home site, or change to a different one completely. Nottinghamshire is probably the most active of the three at the moment.
We're recruiting new Local Editors all the time, but still have plenty of openings and are actively looking for people to fill these roles. Unfortunately we haven't stumbled across any local gurus in those areas yet!
Also, stay tuned for a Gransnet Local FAQ page, which should answer all of these queries about using your local site.