Hi Trevor,
I plan on getting a www eventually. Personally, I'm not so bothered about getting to the top of search engines, but think that a web address included in all other marketing material etc may allow potential customers to find out a bit more about you in order to make a more informed decision as to whether or not to use your services.
I'm thinking of it as another medium which you can use to get your message across. i.e. Leaflet drops through door, customer looks at leaflet, sees www, looks you up on the net. Gives you more space than a leaflet to say what you want. Or I may be totally wrong!!
Regards.
Martin S