I suppose if you see a thread that you think it might be useful to re-visit, you could rate it 5-star, but can you then bring up all your 5-star rated threads?
(I'm thinking of my photo organiser, here. I take loads of photos on a holiday, but by rating just the best as 5-star, I can view just a good selection of each holiday, rather than the whole lot.)
This could be a quicker method than say, trying to locate a thread through the 'tagging' system?
Just a thought.