To implement it'd require logging of who replied to which topic. I'll have a think about how best to do it over night to see if it's feasible to do for all topics.
Although on top of that, there's the problem with layout. The topic listing can seem a bit crowded at the moment. I'm not really sure where an extra icon could be shown in there
Re: Show threads you've posted in (5th Mar 08 at 11:51pm UTC)
Well I've planned to offer a templating system (similar to the mini-profile & info center) for the topic & board listing rows from the start. The templating system still needs some fine tuning and adjusting but I could aim to implement that at the same time as your idea. That way users can always play with its postion to suit their forum.