[galaxy-user] Help with adding new datatype

Hi, I'm confused on how to add a new datatype. I've read the http://g2.trac.bx.psu.edu/wiki/AddingDatatypes wiki page, but it isn't clear what I need to do for a completely new type. Specifically, I want to add a gzip tool to compress and uncompress files to help up/downloading of large files. I've added the following line to the datatypes_conf.xml: <datatype extension="gz" type="galaxy.datatypes.images:Gzip" mimetype="application/gzip" display_in_upload="true"/> But I am stumped as to where I should add the additional information as per step 3. on the wiki page. Can someone help, please? BTW I do code, but not in python. Thanks, Chris