From Salix OS
Salix uses the XFCE Desktop Environment by default, but LXDE is available from the repository and it's very easy to install. This how-to was based on a Salix "basic" installation, so it should work for any system that already has Xorg installed.
You only need to do:
slapt-get -u slapt-get -i lxde-common openbox pcmanfm lxpanel lxsession menu-cache lxmenu-data
You probably want to have some additional tools, too:
slapt-get -i lxterminal lxappearance lxinput lxrandr lxtask obconf midori
That's it! You're ready to log in your shiny LXDE desktop!