Personally, I'd stay away from the all-in-one wonder gadgets.
For a $100-200 you can get a good, basic standalone GPS.
As far as a compass, you'd also do much better with a good standalone model. $50 will get you one heck of a compass.
I had a Nokia phone recently that had a small LED "flashlight", an FM radio, and a camera in it. The only reason I got it was because it was free with the calling plan, so the price was right. What a mistake! I had the *worst* call quality I'd ever had, the camera was horrible, and the FM radio left a lot to be desired. And I'm a big Nokia fan.
My opinion: Get a basic no-frills cell phone, get a quality GPS and a quality compass.