I quickly created an alternate icon that is distinctive in the dock and says a little bit about what the application does. (It's not brilliant, but I think it's functionally a little better). The icon may be used freely for non-commercial purposes.
Alternate Textmate icon http://www.spahr.org/share/textmate_icon.zip
Updated Smarty Syntax (same URL as previous version) http://www.spahr.org/share/PHP_Smarty.tmbundle.zip
James.