This is the original copyhttp://en.wikipedia.org/wiki/Ghajini_%282005_film%29
The 2008 copy was a copy of the 2005 copy (though it had the same director and everything - they were just in different languages).
I watched the 2005 version and found it pretty annoying (because the direction was stupid and I hated all the song and dance crap, the melodrama etc). Though to be fair I haven't watched Memento yet, but I have no doubt that Memento is clearly the superior version.
I'm surprised that Nolan hasn't sued yet too. I think the 2005 and 2008 films (combined) grossed more than Memento.
The 2008 film alone grossed over $38.3 million (apparently the 2005 film grossed $5 million in Tamil alone - it was later dubbed into Telugu too) while Memento grossed $39.7
I really hope the Indian filmmakers get sued so that they can come up with original movies for a change.