Adventure Path Charter Subscriber; Pathfinder Rulebook Subscriber
Is it possible to flank while using ranged weapons? Can a rogue, for instance, throw a dagger at an opponent threatened by one his allies and still get his sneak attack damage?
You'll need to move through cover or concealment, hide, and then throw. Or use the sniper option under the stealth skill, if you can succeed with the -20 modifier.
Another excellent option that I use with my arcane trickster: greater invisibility...everybody's flatfooted to me!