http://blog.csdn.net/shaoguangleo/article/details/6371196
本来还想先换一个源再来更新一下的，不过试了试，发现网速十分理想，也就罢了。
现在似乎在菜单中没有看到软件源的菜单项，在新立得里看到默认大软件源已经自动改成了中国的服务器，再加上放假这几天网速不错，一口气就更新了近一百多M。
顺便搜几个其他的源地址，可以改/etc/apt/sources.list，默认的有：
deb http://cn.archive.ubuntu.com/ubuntu/ natty multiverse
deb-src http://cn.archive.ubuntu.com/ubuntu/ natty multiverse
deb http://cn.archive.ubuntu.com/ubuntu/ natty-updates multiverse
deb-src http://cn.archive.ubuntu.com/ubuntu/ natty-updates multiverse
deb http://security.ubuntu.com/ubuntu natty-security main restricted
deb-src http://security.ubuntu.com/ubuntu natty-security main restricted
deb http://security.ubuntu.com/ubuntu natty-security universe
deb-src http://security.ubuntu.com/ubuntu natty-security universe
deb http://security.ubuntu.com/ubuntu natty-security multiverse
deb-src http://security.ubuntu.com/ubuntu natty-security multiverse
deb http://archive.canonical.com/ubuntu natty partner
deb-src http://archive.canonical.com/ubuntu natty partner
其他的：
SRT Sources
deb http://ubuntu.srt.cn/ubuntu/ natty main restricted universe multiverse
deb http://ubuntu.srt.cn/ubuntu/ natty-security main restricted universe multiverse
deb http://ubuntu.srt.cn/ubuntu/ natty-updates main restricted universe multiverse
deb http://ubuntu.srt.cn/ubuntu/ natty-proposed main restricted universe multiverse
deb http://ubuntu.srt.cn/ubuntu/ natty-backports main restricted universe multiverse
deb-src http://ubuntu.srt.cn/ubuntu/ natty main restricted universe multiverse
deb-src http://ubuntu.srt.cn/ubuntu/ natty-security main restricted universe multiverse
deb-src http://ubuntu.srt.cn/ubuntu/ natty-updates main restricted universe multiverse
deb-src http://ubuntu.srt.cn/ubuntu/ natty-proposed main restricted universe multiverse
deb-src http://ubuntu.srt.cn/ubuntu/ natty-backports main restricted universe multiverse
网易
deb http://mirrors.163.com/ubuntu/ natty main universe restricted multiverse
deb-src http://mirrors.163.com/ubuntu/ natty main universe restricted multiverse
deb http://mirrors.163.com/ubuntu/ natty-security universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ natty-security universe main multiverse restricted
deb http://mirrors.163.com/ubuntu/ natty-updates universe main multiverse restricted
deb http://mirrors.163.com/ubuntu/ natty-proposed universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ natty-proposed universe main multiverse restricted
deb http://mirrors.163.com/ubuntu/ natty-backports universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ natty-backports universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ natty-updates universe main multiverse restricted
ubuntu 11.04 上海源
deb http://mirror.rootguide.org/ubuntu/ natty main universe restricted multiverse
deb-src http://mirror.rootguide.org/ubuntu/ natty main universe restricted multiverse
deb http://mirror.rootguide.org/ubuntu/ natty-security universe main multiverse restricted
deb-src http://mirror.rootguide.org/ubuntu/ natty-security universe main multiverse restricted
deb http://mirror.rootguide.org/ubuntu/ natty-updates universe main multiverse restricted
deb http://mirror.rootguide.org/ubuntu/ natty-proposed universe main multiverse restricted
deb-src http://mirror.rootguide.org/ubuntu/ natty-proposed universe main multiverse restricted
deb http://mirror.rootguide.org/ubuntu/ natty-backports universe main multiverse restricted
deb-src http://mirror.rootguide.org/ubuntu/ natty-backports universe main multiverse restricted
deb-src http://mirror.rootguide.org/ubuntu/ natty-updates universe main multiverse restricted
搜狐
deb http://mirrors.shlug.org/ubuntu/ natty main universe restricted multiverse
deb-src http://mirrors.shlug.org/ubuntu/ natty main universe restricted multiverse
deb http://mirrors.shlug.org/ubuntu/ natty-security universe main multiverse restricted
deb-src http://mirrors.shlug.org/ubuntu/ natty-security universe main multiverse restricted
deb http://mirrors.shlug.org/ubuntu/ natty-updates universe main multiverse restricted
deb http://mirrors.shlug.org/ubuntu/ natty-proposed universe main multiverse restricted
deb-src http://mirrors.shlug.org/ubuntu/ natty-proposed universe main multiverse restricted
deb http://mirrors.shlug.org/ubuntu/ natty-backports universe main multiverse restricted
deb-src http://mirrors.shlug.org/ubuntu/ natty-backports universe main multiverse restricted
deb-src http://mirrors.shlug.org/ubuntu/ natty-updates universe main multiverse restricted
骨头源，
deb http://ubuntu.srt.cn/ubuntu/ natty main universe restricted multiverse
deb-src http://ubuntu.srt.cn/ubuntu/ natty main universe restricted multiverse
deb http://ubuntu.srt.cn/ubuntu/ natty-security universe main multiverse restricted
deb-src http://ubuntu.srt.cn/ubuntu/ natty-security universe main multiverse restricted
deb http://ubuntu.srt.cn/ubuntu/ natty-updates universe main multiverse restricted
deb http://ubuntu.srt.cn/ubuntu/ natty-proposed universe main multiverse restricted
deb-src http://ubuntu.srt.cn/ubuntu/ natty-proposed universe main multiverse restricted
deb http://ubuntu.srt.cn/ubuntu/ natty-backports universe main multiverse restricted
deb-src http://ubuntu.srt.cn/ubuntu/ natty-backports universe main multiverse restricted
deb-src http://ubuntu.srt.cn/ubuntu/ natty-updates universe main multiverse restricted