Generally either enderchests (easy, efficient setup that can carry a lot of stuff quickly), or railcraft+myst portal (complex, inefficient setup with a small loads lot of time lost on each end.)
Oh, and liquids can go through an enderchest fine (tank->deployer+bucket->enderchest).
SSP- You can also install teleport pipes for buildcraft.
and just dropping loose items through a myst portal works fine too.