I'm not familiar with server-side scripting, but I'm currently using a PHP application on Media Temple to cache JPEGs from four webcams hosted on a server located in the middle of the Indian Ocean. (Hence my reason for caching them in the US.)
The webcams are updated every five minutes. The PHP application stores the cached images in http://static.rigic.co/cache/. I would like to create a cron script to automatically delete the contents of "cache" (not the folder itself; just the files inside) at a regular interval.