You may not be aware that when you create the first post of a thread you can include tags in the tag line below the content area. Tags are keywords that can describe your thread and can be used by members to search for threads related to those keywords.
If I create a new thread and it is about staking my WSOP run this year then I may include the tags "staking" and "WSOP" and perhaps "2011". They will show up at the bottom of the thread under the TAGS header. Members can then click on say the WSOP tag and see all the other topics tagged with that WSOP tag.
I've only seen a few people use this feature so I thought i would point it out. Might make searching easier in the future