In Acrobat (this is not possible in the free Reader), you would select the pages that you want to extract in the Page Thunbnails pane on the left, then right-click and select Extract - this will create a new document with those pages that you've selected. You can also select Tools>Pages>Extract, and then specify your page range to achieve the same result.
Now you only have to do a Save As with the new document and give it a name and you are done.
Karl Heinz Kremer
PDF Acrobatics Without a Net
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