I have not ever heard of any laws against a GPS, Since cars have them, why would you think they would be illegal ?
For a mount for your blackberry, look to " Ram Mounts " they have all kinds of stuff. I bought 2 from them ( 1 for car and 1 for bike ) for my Garmin . They are a little higher than some , but after I got mine I was well satisfied with the quality of their products .

Rat

Well as to the legality - I heard tell that earphones while riding are illegal. So I figured it had to do with the distraction or something? I figured I'd be more distracted by a GPS than a set of earphones...so I wanted to know if anyone had heard of a law against them that's all.

Thanks for the direction!