Option to choose fonts in editor

The page editor offers many useful options but unfortunately it does not offer the option to select text fonts. I've had numerous requests from our users to be able to change the font in a line of text easily. It's a common feature on other editors (including web-based editors) to select various fonts.
I know this can be set on the stylesheet using CSS for the various paragraph types or for a div, but what we need is something that regular users can apply to a string within a line of text (or to any selected text on the page).