Leopard has some really great tricks up its sleeve for PDFs. You can save just about anything you can think of as a PDF document (this works in Tiger too), and you can then compile your PDF documents into one multi-page PDF file if you want using Preview.
For example, let’s say you wanted to save a web page as a PDF file. All you have to do is load the page then select:
File>Print…
Once the Print Window opens up you’ll see a PDF button in the lower left hand side of the screen. There you’ll see a variety of options about what you can do with your PDF file.
Select Save as PDF…
Now you can repeat the process by going to another webpage. Once you have two PDF files you’d like to make into one multi-page document simply open the first one that you want to use into Previews then drag the next item you want into the document into the Sidebar.
Once you’ve added everything you’d like to be in your document, and organized how you’d like it to appear Save the file - and BOOM - done.

James
Do you know where you can change the settings for what appears on the PDF, such as the link, time, title etc...? September 22nd, 2008 at 10:43 am
Andrew
On a related note, I've noticed that PDFs that are created/saved by Adobe Acrobat Pro. always open with Acrobat, even when PDFs are set to be opened with Previews. Any thoughts? September 22nd, 2008 at 11:16 am
Tijl Vandersteene
Alfred
Marybeth
iCrater
So I know this is an "easy tip", but how does the drag part work in Tiger without Leopard's Sidebar?
When I was trying this the PDFs were opening in Adobe Reader —
I could open them in Preview by dragging them to the Preview icon in the dock, but there must be a simpler way... related to Andrew's question September 23rd, 2008 at 9:41 pm
Michael
That page doesn't show you how to create multi-page PDFs. There's nothing wrong with reminding everyone about printing to PDF in this post. September 24th, 2008 at 10:13 am
Michael
Hugo