I've long been intrigued by the concept of sat nav, but never really understood much about it. I thought about getting a car with it but never bothered because of the extra £1700 it would cost. However I'm seeing more and more GPS PDA's with Sat Nav software, the likes of Argos have them starting at around £250 now. Which in theory sounds great because they can be used for other things and are able to be used in different cars etc. I was just wondering though if users of Sat Nav could give me some insight into what they're like to use. I've never seen one demoed so don't know how affective they are. What do you need to look out for in a good PDA Sat Nav system? How easy is it to use? How do you choose your destination, just type in the address? Is it true they automatically adjust the route if you miss the turning? Do they "say" the directions to you? How detailed are the instructions/map? Are we talking a rough guide to the location or is it pin point detail? How much detail do they go into, for example if you're coming up to a large traffic island for example, will it say summet like "take the 3rd turning" and expect you to get into the right lane, or will it say something like "get into lane for the A25N" or whatever? I know it's a lot of questions, but I really have no idea about the functionality of PDA Sat Nav, and am wondering if it is worth it. Is it basically a glorified version of multimap.com?