9 leaf piles = 1 leaf block

as I said on MC forum...

• leaf blocks can also be used for several things for Forestry mod and IC2 both of which could use it as a fuel
• IC2 has plant balls which are compressed and then can be extracted for biofuel, same with Forestry which uses biofuel.
• Roots and cattails I guess fit this as well, but roots I think could be used for other things like making mulch and fertilizer for Forestry or possibly even combining them with the right raw materials like sand and making sand into dirt.
• Cattails also could be edible since the roots are after all edible. The fluffy part could be used as a alternative to wool or even be burned.

EDIT: Edited by ScottKillen to refer to issue #16 where the bulk of these ideas will be implemented in a future version.