What about a Value Feature that can be set to a thread by the moderator/admin of that forum. Would be usefull for large boards and referencing for both the mod and visitors.
One sample, a thread is started, looks good so i give it a 8/10 and in the board section, the mod/admin can choice to display a value colum... value could be a color instead of number, or default text displays can show depending on the number value (all options for the mod to pick from)
8/10 good idea

9/10 great idea

10/10 WOW!
*shrug*
a thread could even be organized by how many hit it gets... a visitor could decide to see the thread with the most hits in a decending order... or value order... so more "useful" threads show up first, so they don't have to spend lots of time wading through all the threads to find good topics to read.
Also, if the value of the thread has a higher value, maybe it sticks around longer before being archived (not sure if you archive or not).
Default Value 3 (if a mod assigns lower then 3, then the thread will auto delete after no more post are posted after a certain period)
Just some ideas for running large boards.