Lost!

[Pirate Bill]

Originally Posted by bewitched

2. Desmond hit sideways Locke with the intention of jolting an awareness of island Locke (or NotLocke, as the case may be) since it appears it either takes an interaction with a constant or a life/death experience to enlighten the sideways' conciousness of their island existence.

That's what I'm thinking.

Other possibilities:

3. Desmond is trying to set the sideways world "right." Locke is supposed to be dead.

4. (This was mentioned on the Jay & Jack podcast) Desmond is trying to unite Locke and Jack and have Jack fix Locke's spine.