A galaxy tab in the top of a tank bag would make a good GPS (if it had a stand alone GPS instead of assisted) cos I could see it with out glasses.. 
My partner has just got her new phone. It's a Samsung 580 which is an android phone with all the whizz bang smartphone stuff. As part of the deal a 10.1 galaxy tab was included. To us it seemed a better deal than the Samsung Galaxy Nexus phone which led us to looking for a better deal.
There are two versions of the Tab, one is 3G like and can be used like a normal phone and the other is wi-fi which is the one we have. In simple terms one version is phone based the other is netbook based. I've had both phone and tab connected via our home wireless network. Both can connect to my PC via bluetooth, usb and wifi providing the software is installed on the pc.
Both have A-GPS which is not much use on a wifi only system and use google maps but in the GPS settings menu there is an option just to use GPS for location alone.
Just to see what else was available I did a search for GPS freeware and came up with this
https://market.android.com/details?id=com.navfree.android.OSM.ALL Which I have downloaded and installed on both phone and the Tab. It didn't seem to install the first time so I did it again and it installed then downloaded maps and installed them. Same for the phone. Both worked ok as for GPS showing my location on the map. I have tested the phone for setting route and for guidence to our local supermarket and it worked ok on GPS alone. Also re-routing works as I purposely went past point I had set on the map. The only downside is that it needs a data connection to search for an address, but while your home and connected via wifi or one of the free wifi hot spots then it's ok.
It's free and other features are coming but it does what it says it does, navigates by GPS independant of your network. The tab is to large to go on the bike, but the phone is ok and will do if my stand alone Mio Moov GPS fails.
