Did you know that you can annotate PDFs using Preview on Mac OS X Leopard? It’s a fast and efficient way to share comments when collaborating on group projects.
Under Preview’s Tools menu, you’ll find the options Mark Up and Annotate. To use the Mark Up feature, choose Text tool from Preview’s toolbar then select the text with the cursor, choose a Mark Up option from the Tools menu (Highlight Text, Strike Through Text, and Underline Text).
To add shapes, links or comments, select a command from the Tools menu’s Annotate list (the options are Add Oval, Add Rectangle, Add Note, and Add Link).
You can also Add Note by simply clicking anywhere on the pdf file. A colored tag will appear in the left margin alongside the spot where you clicked. Its default text consists of your user name and the date, though you can alter or add to this by double-clicking on the note. To move notes, double-click their icons (those little cartoon-style balloons) and then drag them. When you double-click a note icon, you can also specify the note’s color and other attributes. To remove a note, double-click its icon and press Delete.