The only thing I need quick access to is my wallet, and that's in my jacket chest pocket with the registration!
My setup changes with where ever I decide to go! When I use the bike to commute to work the two saddle bags are usualy on, and I set them up something like "piperjim" does! If I plan to do some off road, I use the tank bag. At first the tank bag seem to be in the way but like everything else, I got use to it! And then when I go on a long trip, the setup changes again!
And I'm like "From MARS", the cell phone is always on me! I Don't use GPS whatsoever,but if I did, I would probably go with the Touratech setup where you can lock the GPS on the bike, that way it can always stay there!