家里的上网本10英寸屏幕，太小，看电影需要效果，想接到大点的液晶上看，直接插上，本子没啥反应，搜索发现，需要费点时间配置下：需要添加一点配置到/etc/X11/xorg.conf 好让X11识别设备，配置好后的文件如下，添加 --- 说明的地方即为添加的配置信息：

# nvidia-settings: X configuration file generated by nvidia-settings
# nvidia-settings:  version 1.0  (buildmeister@builder63)  Fri Aug 14 17:55:55 PDT 2009

# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig:  version 1.0  (buildmeister@builder63)  Fri Aug 14 17:54:58 PDT 2009

Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "Screen0" 0 0
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
    Option         "Xinerama" "0"
EndSection

Section "Files"
    FontPath        "unix/:7100"
EndSection

Section "Module"
    Load           "dbe"
    Load           "type1"
    Load           "freetype"
    Load           "glx"
    Load           "extmod"
EndSection

Section "ServerFlags"
    Option         "Xinerama" "0"
EndSection

Section "InputDevice"

    # generated from default
    Identifier     "Mouse0"
    Driver         "mouse"
    Option         "Protocol" "auto"
    Option         "Device" "/dev/input/mice"
    Option         "Emulate3Buttons" "yes"
    Option         "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"

    # generated from data in "/etc/sysconfig/keyboard"
    Identifier     "Keyboard0"
    Driver         "kbd"
    Option         "XkbLayout" "us"
    Option         "XkbModel" "pc105"
EndSection

Section "Monitor"
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "CMO"
    HorizSync       30.0 - 75.0
    VertRefresh     60.0
    Option         "DPMS"
EndSection

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce 8400M G"
    BusID "PCI:1:0:0"   －－默认没有这个，添加上。
EndSection

Section "Screen"

# Removed Option "metamodes" "1280x800_60 +0+0"
# Removed Option "metamodes" "nvidia-auto-select +0+0"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    Option      "AddARGBGLXVisuals" "True"
    DefaultDepth    24
    Option         "NoLogo" "True"
    Option         "TwinView" "true" －－默认是0，修改成true
    Option         "metamodes" "1280x800 +0+0"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

==========
添加后，外接上显示器或者投影仪，登录时选在GNOME图形化登录，即可。

如果是需要连接投影仪，那就需要双屏（笔记本和投影仪）都能显示，而且显示的完全一样，必须添加如下（黑体为添加的）：

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "AddARGBGLXVisuals" "True"
    Option         "TwinView" "true"
    Option "TwinViewOrientation" "Clone"
    Option "UseEdidFreqs" "True"
    #Option         "metamodes" "1280x800_60 +0+0"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection