Combine PDFs is a very useful little tool to combine all your PDFs into one.
You sometimes need to join and view all your PDFs, whether to print them out, read or simply organize. While it's not possible to do this with Adobe PDF Reader, you can use Combine PDFs. This nifty tool lets you add an unlimited number of PDF items and merge them. Either drag and drop PDFs into the program's interface or add them via the Finder.
Combine PDFs lets you add a new title to the combined PDFs, change the author and creator. You can search files in preview mode and sort by page number. The latest version of the application handles JPEGs and PNGs in PDFs much better as they are no longer recompressed. Do take into account though that the more PDFs you want to merge the more time the process will take.
All in all, a clever tool to have around to merge PDFs into one.