What is "Roundaboutness" and how does it relate to time-preference?

Bohm-Bawerk, of course, formulated a theory of “roundaboutness”. However, his ideas differ somewhat with Menger’s and Mises time-preference theory of time-discounting. Essentially, what is roundaboutness, how does it differ with Menger and Mises’ variation on the theory of time-preference, has it been refuted (this question is looking toward Paul Samuelson’s critique in particular), and what was Knut Wicksell’s take on roundaboutness and Bohm-Bawerk’s theories in general? Sorry if I’ve worded the question terribly or made serious errors in my inability to grasp these concepts.

You might find this interesting; http://mises.org/daily/1965

In part its Rothbard criticising Fetters position on interest, which necessarily involves considerations of Fetters critique of Bohm-Bawerk.

Using your web browsers function to search the text on this page for ‘roundabout’ will jump you to some very insightful (and short) paragraphs of things to ponder

Cheers, the Fetter page was a great find. I sort-of get the idea of roundaboutness, but the differences between Bawerk and Menger and co. threw me off a bit.

There are still those today who choose to use a scythe rather than a combine. Why would they do that?

I have a wheat allergy so it really makes no difference to me.