295 characters. Can anyone come up with a shorter one? 
$_="- - -\n"x3;
$"=o;W:while($"=($"eq x?o:x)){$i=0;$O=$_;$O
=~s/-/$i++/ge;print$O.$";$H=<>;$w=0;s/-/$w++==$H?$":$&/egs
;$B=$_;for$P(o,x){s/$P{3}/$&/;s/($P . .\n){3}/$&/;
s/(. $P .\n){3}/$&/;s/(. . $P\n){3}/$&/;
s/$P . .\n. $P .\n. . $P/$&/;s/. . $P\n. $P .\n$P . ./$&/;
last(W)if$&=~m/o|x/}$_=$B}print

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In reply to Tic tac toe by Jeff Connelly

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