Modify notification in Ubuntu

First, update+upgrade the patch for allowing customization on notify-osd package.
http://www.webupd8.org/2010/07/patched-notifyosd-updates-option-to.html

Manually customization
http://www.webupd8.org/2010/05/finally-easy-way-to-customize-notify.html

PPA version of "notifyosdconf" editor is also available (but not for Maverick)
http://www.webupd8.org/2010/05/new-notifyosdconfiguration-version-gui.html

So, only option left is to compile it myself
http://www.webupd8.org/2010/05/gui-to-configure-notifyosd-in-ubuntu.html