Knowledge, Truth and Use Value

What does it profit us to discover some truth if we have no practical use for it? Conversely, if we derive practical benefits from some piece of knowledge, why would we worry as to its truth?
In this article at the Bubble Chamber, Boaz Miller discusses knowledge and practical interests and considers arguments for the assertion that “whether a person knows a certain claim depends not only on the truth of the claim and the evidence she possesses to support this claim, but also on facts about her practical interests and social values“.
One thing I do have difficulty with here (and maybe this is because I haven’t read the books that Boaz cites in his post) is the relationship between knowing and believing. Boaz considers the argument that “if believing a certain claim gives you sufficient reason to act on your belief, then this belief is knowledge“. Does this mean that knowing something involves acting as though it is true, possibly in a way that involves bearing a cost if one turns out to be mistaken, whereas believing means merely asserting that something is true without putting it to the test in a way that might incur a cost if one turns out to be wrong?
Either way, I think these considerations are important in the way we talk about and use scientific knowledge. Even if one believes that science can tell us some ultimate and objective truths about the world, one has to concede that many theories held today will eventually turn out to be wrong in some way (even if only in the fine details). Nevertheless, one frequently has to decide on actions to be taken right now and the theories one has right now are all one has to go on. Therefore, one will act as though one believes the theories to be true, even if one also believes that they will most likely turn out not to be strictly true at some later date. The level of confidence one has in doing that will depend on how much information one has about the extent to which the theories involved have been tested (and the extent to which one believes that information, of course). If one believes the theory to be good enough for one’s immediate practical needs, then one can proceed to act as though it is true, regardless of whether one believes it to contain some fundamental objective truth about the world or not.