Here's one of the little server mods I worked on over thanksgiving: flowGrab
flowGrab patches the server to also allow grabbing liquid flows (ie, non-source liquid blocks) with a bucket, and that includes buckets in dispensers. Non-source liquid in a bucket does not become a source when placed, it just flows away, but it does mean you don't need to sacrifice a source block to get a water bucket or a lava bucket.
This is no big deal with water, really. Water sources regenerate in Minecraft. Lava sources, however, do not regenerate. Use one up and it's gone.
I think you see where this is going.
It means you can grab as many lava buckets as you want out of a flowing lava stream, and use them to power furnaces.
It also means you can use a single lava source to power a machine like an autosmelter indefinitely.
WHOO SUSTAINABLE ENERGY! Your world's industrial base is no longer limited by however long it takes to completely mine out the Nether!