A ranking by popularity might help finding useful postings.

I beg to question the premise :)

IMHO, the popularity of a node as measured by the voting system is not necessarily related to its usefulness for solving the problem you set out to find nodes for.

Even if all monks voted with good principles in mind, there would still be the exposure factor having a considerable influence on the final rep of a node. This is not only related to whether a node is frontpaged or not, but even more to when a reply is being posted. I've seen quite a few excellent replies being posted one or two days after the thread had been started, and in most cases they only got very few votes (below 5, if any at all). Had they been posted immediately as the first reply, I'm pretty sure they would have 'scored' a lot better. In any case, those nodes would definitely fall through the cracks when you rank by popularity.

Another factor influencing rep is how easily a node can be understood. Nodes that require too much thinking or reading get less votes on average (of course there are exceptions). More complex and lengthy explications thus suffer from this penalty, irrespective of how well and to-the-point they're written — some issues just require more words or code. On the other hand, it's exactly those nodes that might help solve your problem, rather than the umpteenth repetition of trivialities you can also find in the regular docs.

As far as I could observe in the time I'm here, both of these factors have a high influence on the rep of a node, but are virtually orthogonal to potential usefulness.

Note that I'm not complaining about the voting system (for heaven's sake, leave it as it is), I'm just saying that rep might be a bad measure of usefulness or 'quality' of a node.

I'm well aware of the limitations of the voting system, that's why I said "might help".

But I'm pretty confident that sorting by reputation can be "more useful" than sorting by time.

Anyway usefulness is in the eye of the beholder and can't be measured objectively ...

And if it's not possible to search by rep, why do we bother to collect them, only to keep people busy and interested in the XP-game???

For completeness, after playing around with google's sitesearch I was able to find some useful posts... ranking pages by links pointing to them is not too bad... 8 )

Cheers Rolf

But I'm pretty confident that sorting by reputation can be "more useful" than sorting by time.

I wouldn't be so confident :)  Actually, I think using other means to narrow down the search (additional keywords, etc.) such that sorting of the remaining hits becomes more or less irrelevant, is the better strategy.

And if it's not possible to search by rep, why do we bother to collect them, only to keep people busy and interested in the XP-game???

I'd say, yes, it's the game, and its - hopefully beneficial - side effects (others might disagree, though).  Or maybe somewhat more favorably put: rep can give some kind of community feedback, if you factor out the counterproductive influences (exposure, etc., like I mentioned above) for yourself...