Krapht's Logistics Pipes is an extensive overhaul of the Buildcraft pipe system. It allows for better distribution of items via pipes, more organised stockkeeping and easier automated crafting.
You can get the latest version from this mod on the Downloads page. Note that there only is a SSP version.
If you want to use Logistics Pipes in combination with other mods, you should have a look at the page for interaction with other mods.