Choose from Text Only, Icon Only, or Text and Icon by holding the Command/Apple key while clicking the Toolbar widget (the oblong button at the top right of the window). This allows more than the usual 8 or 9 items.
This should also work for any Cocoa Application using Toolbars.
Now that I think about it this is probably old news. But it's news to me. Enjoy...
[Editor's note: It's news to me, too ... and I couldn't find a previous mention of it here, so perhaps it's news to more than just two people!]

