I have written an ebuild that allows semi-automatic installation (and removal) of the LabJack LJM driver and library and (if desired) Kipling and the software examples in Gentoo Linux. This entails the x86_64 (Intel 64-bit) version only for now, but it should be easy to include other architectures. It should also be easy to create a PKGBUILD for Arch Linux from its ebuild.
The package is available from the AstroFloyd unofficial Gentoo overlay as sci-electronics/labjack-ljm-64bit as follows:
layman -a AstroFloyd
emerge -va sci-electronics/labjack-ljm-64bit