Go to your admincp --> Forums & Moderators --> Forum Manager
Click Expand All under your Forums (if not already expanded).
This will show a list of all your Categories, and subsequent forums
(Category being the first under the FORUM title of each header) and if you hover over each link (left side) it will display the forumID near the task bar.

Thanks!
Another question! How do you get your subforums to look like yours? Like the - in front, did you manually add that?

Thanks for your help! I'm loving this mod!

Yes, For the subforums, I just added a hyphen - and a space.
Forum
- Subforum

Thank you so much! This ROCKS! I love it.
I so appreciate you doing this :)

so i can get this working for Photopost pro?

Do you mean as for linking to your gallery?

no i meant for my photopost categories

If each category has a link, I don't see why not - I would treat it as any other (just as I did for my own subforums) format it however you'd like. I used forum categories as headers because in the forumhome page, they act as headers there.

Edit: You could even try something like td class="thead" in the code for each category to change things up a bit - :)

fantastic hack. thank you so much

*installed*

Looks just like digitalpoint