I use a Lowrance GPS which has a map built in. WIth there software (aditional money) you can download more detail of the area of your choice into it (Some Gormans will also let you do this). This works OK for when were doing local trips, and I need my wife to tell me "the turn you are looking for is getting close".
On long trips we use the Laptop with the GPS. I use Delorme Street Atlas version 7. I tried version 8, but there are actual mistakes on different route numbers on the map. This could really screw you up if the computer tells you (yes, it uses real voice to talk to you) to make a RT on rt 66, but the real name is rt 41!
Also the map and go program they sell is nice, but does not have the small/back road detail of the street atlas versions.