For the reason that Cory mentions, I always require a contest of maneuver skills when one character tries to outmaneuver another, e.g. circling around to get behind them. It's not that running around on an even, flat, paved surface is difficult, but the rolls show which character is doing it better. So instead of a "Chinese checkers" approach where we go one at a time in artificial fashion, I depend on the character's skills and rolls to see how well they do.
That is a simple way to do it; do you find it slows the game down though JDale? How often are you rolling for these things, and how do you decide specifically who gets to move where? For example, if someone is trying to maneuver to someone's rear, and the mover beats the stationary target's roll by say 5, how do you decide how far to the rear he gets? Is there partial success (e.g. he gets flank not rear), or what would be the threshold for full success? Or is that just decided on an ad hoc basis by GM judgement?
Questions like these are perhaps easily answered, but personally, I prefer a system that doesn't need a lot of rolls or GM adjudication, because I feel these things slow down the game and add an element of judgement that can cause friction between GMs and players.
You really only need a roll for the things that are interesting. Do I get flank? Does that foe get flank on me? Am I able to get past that foe, or stop that foe from slipping past me? So if a roll happens, which I don't find is particularly often, it's something that is often interesting to the player and adds a little suspense.
It does mean the game is more like a roleplaying game with skills and less like a combat board game. That means more decisions by the GM.