In the near future this site will contain a searchable managed list of user submitted themes. Themes will be cataloged by main function (for example photoblog or photo gallery) but will also indicate theme files (skins) included for any of the PhotoTilts extendable features and plug-ins.
I'm going to start this list off showcasing all of the included core themes along with a very basic theme which should be helpful for those looking to develop there own photoblog theme or photo gallery theme.
However some really graphically/design talented individuals who what to start developing themes now (perhaps even for bundled release with PhotoTilt) email jjthemes[at]phototilt.com. A pre-release version might be obtainable for those individuals that are so inclined.