Theme Sites
- deviantART.org
A large collection of themes for Openbox.
- Box-Look.org
Another large collection of themes for Openbox and other *box type window managers.
- Customize.org
Screenshots of many Openbox desktops with various themes.
- Our Screenshots page
View many screenshots of users' Openbox desktops, and submit your own.
Theme Authors
A number of Openbox theme authors have websites for their own theme collections:
Theme Tools
- ObTheme
A GUI editor for Openbox themes. 
- ThemeUpdate
A simple tool to create an Openbox theme from a Fluxbox/Blackbox theme. This tool works only for themes that do not use XPM images to fill the decorations.