This simple system is easy to configure and is safe to use. some of the features it has: Multiple files upload, Extensions check, Extensions attributes, Max file size control, ability to change mode of uploaded files, Email notification of upload attemps, Universal password protection, action logging and of course FREE ;) the script is very simple (as its name says) and is heavily commented! so modifying it would be easy.. comes with readme file that will guide you in installing the script.