This little style is similar to Link Alert extension for Firefox (the extension is better).
When mouse is over a link to DOC or PDF file the cursor change and an icon to this file type appear.
I hope to add other file type (ZIP, EXE ect).
The style works only with direct link to files not with javascript link.
To write this script I have read:
http://www.askthecssguy.com/2006/12/showing_hyperlink_cues_with_cs_1.html
and I have used the data URI Kitchen:
http://software.hixie.ch/utilities/cgi/data/data
To work it need to use base64 encoding (Thanks to Jason Barnabe and Weishu for this trick).