升级Ubuntu 11.04后一直搜索不到无线网络，用自带的驱动无法工作，也试过好多方法，自己编译wl，还是失败。
最后解决方法
Add a "contrib" component to /etc/apt/sources.list, for example:
# Debian Squeeze/6.0
deb http://ftp.us.debian.org/debian squeeze main contrib non-free
Update the list of available packages and install the wireless-tools package:
sudo apt-get update
sudo apt-get install wireless-tools
Install the appropriate firmware installer package:
For 802.11b/g devices with a BCM4306 revision 3, BCM4311 or BCM4318 chipset, install firmware-b43-installer:
sudo apt-get install firmware-b43-installer
For 802.11b/g devices with a BCM4312 LP-PHY chipset (PCI-ID 14E4:4315), install firmware-b43-lpphy-installer:
sudo apt-get install firmware-b43-lpphy-installer
The necessary kernel module should be automatically loaded.
当然你自己可以加载
sudo modprobe b43
OK,无线网络的指示灯亮了，驱动安装成功！
注：一旦开机无线模块不自动加载，可以在配置相关文件/etc/modules中加入
b43