text/html            /gnome/share/doc/libgnet1.0-dev/html/index.html   
text/sgml            /gnome/share/gnome-xml/html/gnome-xml/index.sgml
text/x-troff         /gnome/share/gtkrc.tr
text/x-troff-man
text/x-troff-man-me
text/x-troff-man-ms /gnome/share/gtkhtml/keybindingsrc.ms
text/x-vCalendar   /gnome-source/evolution/calendar/gui/test.vcf
text/x-vCard


text/richtext
text/x-tcl


Other stuff to handle in the future:
application/pdf
application/ps
application/x-applix-spreadsheet
application/x-applix-ord
application/x-asp
application/x-gnumeric
application/x-theme
message/x-gnu-rmail


source code mime types
text/x-idl         
text/x-c? 
text/x-c++
application/x-cgi
text/x-csh
text/x-dcl
text/x-dtd
text/x-emacs-lisp
text/x-fortran
text/x-java
text/x-gtkrc
text/x-makefile
text/x-perl
text/x-python
text/x-scheme
text/x-sh
text/x-sql
text/x-tcl
text/xml ?

Other stuff maybe useful to intelligently parse at some point
text/x-authors
text/x-copying
text/x-credits
