I was trying to create a discussion forum.

I see a discussion board on sharepoint 2007. But my intension is to have multiple topics exclusive to eachother.
Very similar to how this forum looks.

Forums
user forums
topic A
topic b
topic c
developer forums
topic A
topic b
topic c
general discussion forums
topic A
topic b
topic c

DO we have any webpart that comes with sharepoint 07 to do this. I looked at blog categories but it is even close to what i am look for.
Please guide em on this.

Thanks
Siva.