If you have made a Tiki theme and would like to share it with others, please contact us (chibaguy - or post in the forums here). Please register at tikiwiki.org if you haven't already done so (user accounts are distributed from there using InterTiki).
If you want to release the theme under the LGPL license and let other people collaborate on its development, you can add it to the Tiki Mods Subversion (SVN) repository. (More information here). You can either add your theme to the repository yourself, or just make a forum post with that topic and we will do it for you if you like.
When your theme is available for downloading, you will be notified. If you like, you can make a blog or wiki page or just post in the forum here to describe the theme and/or answer users' questions about it, etc.
We would also like to let people (potential customers) know where they can find commercial themes for Tiki or designers/programmers for Tiki-related projects. If you are in this business, feel free to register here and share the details. As needed, a Commercial themes content category will be added, along with appropriate navigation links, etc.