I fear the problem with flitering by thanks (or 'no thanks' if we used it) would be that people will thank or not thank opinions they agree/disagree with. Threads could thereby become very one-sided.

The idea of 'summary' posts which are marked and findable is brilliant except for the question of whose job that is, and when they're made. Would it fall to the OP? The mod? The first person to think the thread is getting a bit long? (and could the summary also be subject to biased interpretation?)

The idea of 'quick threads' would also be good, except they don't necessarily allow for the needs of developers who want to see the way something has developed. Unfortunately, it's not always easy to predict before a thread starts whather it will need a long discussion or a quick one.

How about a poster button to distinguish between 'I said something useful' and 'I was just chatting'? Some of those trheads get filled up with gossipy stuff, and the posters (me included) know we're just posting and not actually adding anything of substance. 20 pages down the line, you could filter out the 'I agree' posts that way?