5/10 Turn Continuation Bet HU with a Gutshot?

This is a common situation, do I continuation bet the turn in late position HU? Against a opponent that autocalls the flop I would, but against an unknown... Anyway here is an example hand below, let me know what you think. I have no reads on these guys.

What are some situations that you would be more/less inclined to do a continuation bet on the turn?

Party Poker (6 max, 4 handed) converter

Preflop: Hero is Button with A[img]/images/graemlins/heart.gif[/img], T[img]/images/graemlins/club.gif[/img].
UTG limps, Hero raises, SB/UTG calls.

Flop: 9[img]/images/graemlins/spade.gif[/img], K[img]/images/graemlins/club.gif[/img], Q[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
SB checks, UTG checks, Hero bets, UTG folds, SB calls.

Turn: 6[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
SB checks, Hero checks.

River: 5[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
SB bets, Hero folds.