Use your VPS as a backup server
Setup your own FTP server
LibreNMS, Cacti, Observium, Nagios
Setup your own proxy server. Squid
Require a desktop GUI?
Setup your own virtual private network
A web-based interface for system administration for Unix. Setup user accounts, DNS, file sharing and the program is freeware.
Hoopla Hosting uses OpenVZ for all its VPS services.OpenVZ is container based...