Sinsull, I have never had tangible experiences like yours but I never feel so close to my grandmother, dead thirty years, as I do when I bake apple pie- she doesn't seem to mind that I've changed her recipe over the years! And my grandfather was a Methodist minister- he seems to positively beam whenever I'm in a Methodist church- it doesn't happen often, but I'm pals with the choir director and he sometimes asks me to sub for him.
Is it my imagination? I do't think so. Those we care about are so deeply connected to us in life that the connection continues after they're gone. Maybe it comes from within me, as I've never had "visits" such as others have told, but that doesnt' minimize their impact.