adding an icon

[Lucy]

is there anyway that you awesome mod folks could add a little icon on the index page for the threads we have posted in??  I am a member of another forum (fishtankforums.com) that does this and it really helps to keep track of posts that you have responded to.  It's pretty basic, they just put a checkmarked box next to the listings to which you have responded, so you know you have a post in that thread.

Just a suggestion.
Thanks guys!
Lucy