Beemoboard is a PHP image board I've been working on for a few weeks. It's still a work in progress, but the basic functionality is there. Here are some features (not all of these are 100% completed, but will be soon. Also note that there will certainly be more features added in the future):
Threads as CSV files Image uploading and thumbnail creation Global config files for misc. settings Math based CAPTCHA-like humanity verification Theme support Automatic or cron based thread cleanup/deletion.