Do you ever have two or more PDF documents that you’d like to merge together into one single PDF? It’s actually very easy to do this with Preview in OS 10.5 Leopard. I’ve not tested merging PDFs in Preview with Tiger, but I suspect it works.
To do this, open one of the PDF’s in Preview. Make sure Preview has the Sidebar open. Open the Sidebar in Preview by clicking View > Sidebar, or by clicking the button at the top of the Preview window labeled “Sidebar.”
Now, drag the icon of the second PDF from your Documents folder or Desktop (or wherever you have the PDF stored) into the Sidebar of the open PDF in Preview. That should be it – you’ve now got a single document with all the pages of both PDFs. Depending on the permissions of the PDFs, you can reorder pages as needed. Make sure to save the PDF with a new name by clicking on File > Save As in the menu bar.
Note that if you have duplex printer that’s capable of printing both sides of a sheet of paper, you can use this technique to make single-page PDFs into two-sided documents. You’d then typically select Long Edge Binding under Layout when you print the PDF to get a two-sided document. This is a easy way to save paper when you have two separate single-page PDFs to print.