[pct-l] SPOT, Bears, and cats (east coast backpacker)

[jauquin quizorro]

Section hiking from Tahoe south through the park this summer.  In three day incriments.  Easy easy.   AT section hiker.   NJ NY CN.  

How are the bears out here?  And I don't have any experience with cats?

I am hiking alone.  My hiker friends are suggesting a thing called 
SPOT
Lets people back in the world know where you are and that everything is fine.  Seems like a good idea, and the price is right.

Any one have any experience with this quasi-cell phone?