Why go ultra small and hard to see? Charting and navigating on a Blackberry, or other phone with 3G is a problem with those micro screens. Just get an aircard and use a notebook. In the US, it's relatively cheap and works in most places that aren't too isolated. When you do that, then you can get the best desktop software and use it properly. If you must go hiking in the wilderness, go hiking when the market is closed or close your positions and take off for a couple of weeks.