I bought the
Garmin StreetPilot c340 and the optional traffic report service and really love it. It works great and updates are easy to do from a Mac or PC.
It's real easy to learn and use and works fantastic.
Neighbor bought the slightly more expensive Garmin and, in addition to a few other features, it has the newer better satellite chip that works much better indoors and in marginal areas. Mine works perfect here but it does loose signal indoors and in parking lots. He bought one of the ones
on this page from Circuit City, can't remember which model but it is one of the ones with the wider screen and it is flat enough to put in your pocket for using when walking.
Shop around as you can find them for a lot less online.