My theory about GPS navigation systems goes like this: the bigger the screen, the easier it is to read, and the less time you have to spend focusing your eyes on it instead of the road. Again, it's just a theory.
Big-screen models used to cost hundreds and hundreds of dollars (and many still do), but TigerDirect has the Magellan RoadMate RM1700 7-inch GPS for $99.99, plus $3 for shipping. That's after applying coupon code EQB31039 at checkout. (Note: I first spotted this deal yesterday, so I'm not sure how long the code will be live.)
A nav system this big requires a fairly big vehicle; VW Beetle owners need not apply. It's better suited to trucks, RVs, minivans, and other vehicles with deep, wide windshields. The RM1700 can be mounted to one or to the topside of your dashboard.
Obviously the big screen is the RM1700's claim to fame, but the unit has a few other noteworthy features as well. Among them: a large onscreen keyboard (natch) that makes address entry and POI searches much easier than on smaller GPSes, and a built-in AAA guidebook for finding things like hotels and attractions.
One thing it's missing: a traffic option. If you want a nav system that can alert you to and/or route you around traffic tie-ups, look elsewhere. Likewise, if you want one that can get out of the car and go for walks, this isn't the best choice: battery life is extremely short.
For a more detailed look at the RM1700's pros and cons, check out CNET's review.
Although this is a refurb, Magellan backs it with a full one-year warranty, same as new units. What's more, you still get a 30-day map guarantee, meaning you get to download the latest maps after you unbox the RM1700. Pretty awesome deal on a big, big GPS.
Bonus deal: Speaking of awesome, I suspect these will sell out before lunchtime: today only, Woot has a refurbished 2nd-gen Kindle 3G for $89.99, plus $5 for shipping. Features include a 6-inch display, free 3G, and a one-year warranty. Nice gift item for your favorite dad or grad!