Swimming is a really good low impact exercise and especially beneficial to anyone who has any musculoskeletal problems who will benefit from swimming or even just doing exercises in the water. You often find that some council run pools can be a little chilly, which doesn't help if you're a bit creaky, often hotels/gym have warmer water in their pools, or see if a local hospital has open hydro pool sessions.
Have a look online for free pedometers, a lot of organisations/companies often give them away
Keep up the great work folks
Edit: Free pack for walking including a pedometer here though it seems to be restricted to certain areas at the moment
http://www.getwalking.org/get-walking-pack/