Mark, you have probably sparked off yet another debate about Sat Nav with 'Old Curmudgeon' posting the fact that he has been driving with an AA Map that cost 4/6d for the past 93 years and never taken a wrong turning in his life.
Truth is, Sat Nav, if used properly, is brilliant and with prices coming down all the time I'm sure they will be fitted as standard equipment on all cars very soon - just like the days before radios were standard. You set your destination, either by giving an address, a postcode, a point on the map or a local point of interest and let Jane (or whichever voice you choose) guide you there by giving clear instructions at every junction on your route. If you take a wrong turning or think the suggested route may not be suitable, you just follow your nose and within a few moments the Sat Nav recalculates the route and gives you alternative directions.
I decided on TomTom because of all the reviews I read but there are other makes, most noticeably Garmin. Remember, you get what you pay for and features you find on the TomTom Go 700 (one of the most expensive) won't be on the Acme Bargain Basement edition. However, all systems offer the same basic voiced route guidance.
The TomTom is standalone and you can even use it walking around town. It sits in a cradle on the dash and picks up signals from satellites so that it can pin-point its own position. This is then superimposed on a map and the computer works out which direction you need to go. Additionally you can download information about speed cameras, car parks, supermarkets, even traffic jams - you name it - and the Sat Nav tells you when you are approaching any of them.
An alternative to the standalone units is to use a hand-help PDA computer (IPAQ or similar) with an attachment. Same end result and some find this fiddly, other find it ideal. Take a look at tomtom.com or garmin.com for more details.
Getting from London to Birmingham is dead easy with even the poorest map. But try getting from a specific cul-de-sac in SE London to a specific postcode in Birmingham and you will need a whole host of maps, A-Zs and directories. Sat Nav does it in one.
Of course you can manage without a Sat Nav, same way as you can manage without a car radio, heater, air-con or even flashing indicators. But it's much better with.