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:
Safari Al's themes
nightm4re's themes
David's themes
Crimeboy's themes
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.