nether fuel is a fuel that when burned makes 20,000 eus first you macerate netherack dust its crafted like hyd coal dust and makes hyd. netherrack dust then commpresed to make commpressed hyd netthrak dust and made into fue
Netherrack is too easy to get.Netherrack fuel is overpowered
Perhaps merely something similar to Nethercoal in "Better than Wolves" ? Craft a lump of coal with a block of Netherrack.
I assume once IC2 comes out, MineCraftForge will allow one to install both, and that the native furnace code would make it so Nethercoal would burn in IC2 generators -- allowing for a bit of an EU return on your Nether investment. I don't have numbers for nethercoal, so I'm not sure how much more EU would result.
If you are looking for jetpack fuel, I think there was something in a blog post about an electric jetpack, so this might work there too.