How can I highlight text on Adobe PDF documents?

I use Adobe Acrobat 7, and tried searching the help menu. It told me to add the 'highlight' icon from the 'comment toolbar', available from the 'comment %26amp; markup' button. Trouble is, I can't seem to find it under the View or Toolbar functions. Thanks.How can I highlight text on Adobe PDF documents?
If you're using Acrobat Reader on Windows, you can right click your mouse to bring up a menu, and then select ';Select Tool.'; When you return to your document you'll have an I-Beam cursor that allows you to select text. This is also assuming that the PDF is selectable (i.e., not a scanned image).