Found this out.
On the 1.9 Pre-Release 3 version, if you use the seed 1027748776332260843 it will place you on a small island with some grass and two trees. No animals.
Its a super challenge. Since there's no wool, you can't make a bed. Here's the kicker; if you die, the game will respawn you 3000 units away from spawn with no land in sight at all. It's like hardcore.
CHALLENGE:
Be well self sustained with a farm, a two story house, and several trees.
Play it on Normal, no switching difficulties, don't be a pussy with hacks, mods, or cheats. The starting island is the only island for many miles with trees. Building at spawn is best since time is also a factor with hunger and starving.
Unfortunately, this seed only works with 1.9 PR3.