You river the nut straight...

[baronzeus]

but make a flush. Villain laggy but not in a ridiculous way.

PokerStars 2/4 Hold'em (6 handed) converter (http://www.selachian.com/tools/bisonconverter/hhconverter.cgi)

Preflop: Hero is UTG with A/images/graemlins/spade.gif, T/images/graemlins/heart.gif.
<font color="#CC3333">Hero raises</font>, <font color="#666666">2 folds</font>, Button calls, <font color="#666666">1 fold</font>, BB calls.

Flop: (6.50 SB) 5/images/graemlins/diamond.gif, J/images/graemlins/diamond.gif, Q/images/graemlins/spade.gif <font color="#0000FF">(3 players)</font>
BB checks, <font color="#CC3333">Hero bets</font>, Button calls, BB calls.

Turn: (4.75 BB) 3/images/graemlins/heart.gif <font color="#0000FF">(3 players)</font>
BB checks, Hero checks, Button checks.

River: (4.75 BB) K/images/graemlins/diamond.gif <font color="#0000FF">(3 players)</font>
<font color="#CC3333">BB bets</font>, Hero

[ghostface]

...raises and calls a 3 bet?

[Your Mom]

you could go for an overcall. seems just as good here, although button may fold for 1 anyway. I think I just call against anyone decent and raise against anyone who is a fish.

[Surfbullet]

I'd raise the river. If villain is LAGy he'll often raise a FD on the flop, especially once he's trapped the field for 2. He'll call a raise with most pairs I imagine, and you may get a loose call out of the BB because of the weird action. If there were more players left to act I'd consider overcalling.

Surf