Recently, completely by accident I found phpVirtualBox a web-based VirtualBox front-end to VirtualBox written in PHP. From my point of view it is very useful project as it provides easy way manage virtual machines on the headless server or any other spare machine you have access to.
Installation was very easy, however I needed to download phpVirtualBox 4.1-11 as Debian Wheezy provides VirtualBox 4.1.
It is worth to note that phpVirtualBox provides a number of interesting features like LDAP authentication, custom VM icons and advanced settings.