We use the Garmin Street Pilot 2720. Works great and it fits on the dash board mounted to a heavy bean bag. It is portable.
It tells you where to turn and what street to turn on just like the commercial. Don't know how I got along without it. Best place I found to buy it was on the Wal-Mart Web site. It was about $450 on sale and listed at $899.
We also have a lap top for use at the campground. Seems like using a lap top to navigate would be a pain. The garmin takes up about 4" of space and the driver can see the route as he/she drives.
I use a laptop for many things (such as right now!) but not any longer for my GPS. I have a GPS that I use for hiking so I bought the software to run on the laptop. It works OK, but the computer had to sit on the dash to be usable and that put it much too far from the driver in our class A motorhome to be must use. I couldn't see it for the glare of the sun, it was difficult to hear and it slid all over as we traveled! The only practical way to make the thing work was to have my wife serve as operator, which she really did not like. When we tried to use it in our Honda CR-V, there was nowhere to put the thing that was at all visible to me and Pam did not want it on her lap! The result was that we tried it several times and the my wife went out and bought me a dedicated GPS that actually can be used by the driver.
I use a laptop with Microsoft streets and trips. It's great for laying out trips, changing routes, stuff like that. but for navigating with it I'm not really sold. Depending on where you put it a sudden stop could be a disaster. I'm leaning toward a GPS because I think it would be safer and more practical to navigate with.
I use the lap top for planning the trip, but then I put in the day's destination in the GPS (Garmin IQue, also a PDA) for actual travel. Laptop is just too ungainly to use conveniantly while travelling (by the driver, anyway)
I use the Magellan GPS. Basically for the same reasons as Kirk listed. Its small enough it'll fit on the dash and not obstruct any views, portable so we can take in the the toad and the cost was reasonable.
I travelled the USA for a year till a month ago (now back in Australia) and used the GPS (Garmin) all the way round the country. It was an absolute marvel and a marriage saver. The information available for directions, shops, restaurants etc still leaves us speechless with amazement. Has to be one of the marvels of the modern age. We used it in the motorhome and swapped to the toad once we had reached the RV park. Also took it with us when walking around a new city which would be difficult with a laptop. Definately GPS is the way to go and we're looking forward to switching it on again next March when we catch up on places we missed this year. Amazing country to visit and great people - thanks for the hospitality and the tips we picked up on this forum.
I lent my Garmin to my son so he could find his way back to his house. He used a laptop untill his wife and him went shopping at Wally world and the unit was broke into. Now he can go any and everywhere with it. In the TT or truck. By the way he found his way back to my house.