change the type of searches. for instance you can search just certain parts of the forums, search for certain peoples posts (authors mainly). or you can just click peoples profiles (say your looking for a certain post) and just have a look at all the posts they have made.

phpbb search function for the forum is not that great but you can experiment with it to to get better results. you could even use google. the google bots tend to come here very quick and cache alot of topics.