This small extension will let give you a list of all the fonts in a document. This is particularly useful when you are moving an SVG file from one computer to another and don't have all the proper fonts installed.
To install it on Linux, Unix or Mac OS X, fire up a terminal and unzip the content of this file inside of your home's .inkscape/extensions folder. If you don't know what I'm talking about, you can try the following lines (without the '$'):
$ mkdir -p ~/.inkscape/extensions $ cd ~/.inkscape/extensions $ wget http://tamentis.com/hacks/inkscape/files/inkscape_list_fonts_2010-04-21.zip $ unzip -o inkscape_list_fonts_2010-04-21.zip
You can then access this feature through the Effects -> Text -> List Fonts menu. If you can't get it to work, just drop me a mail.