机器长期开着浪费，借给别人用又怕安全问题，那就弄个虚拟机吧，然后远程桌面给别人用，效果还是很不错的。
一、安装虚拟机
在下面找到合适的一行添加到/etc/apt/sources.list
deb http://download.virtualbox.org/virtualbox/debian oneiric contrib deb http://download.virtualbox.org/virtualbox/debian natty contrib deb http://download.virtualbox.org/virtualbox/debian maverick contrib non-free deb http://download.virtualbox.org/virtualbox/debian lucid contrib non-free deb http://download.virtualbox.org/virtualbox/debian karmic contrib non-free deb http://download.virtualbox.org/virtualbox/debian hardy contrib non-free deb http://download.virtualbox.org/virtualbox/debian squeeze contrib non-free deb http://download.virtualbox.org/virtualbox/debian lenny contrib non-free