Choosing a topic for phD

J

hi all!
I did my bachelor in biochemistry n will be starting my 1 yr masters in UK in Molecular medicine from september'10 and i want to follow it with a phD. I'm told to look for phD options as early as coming sep- nov. The problem is that its too early for me and I dunno which subject/ topic I should choose for doing my phD!!
What should i do/ read that can help me decide..Please help!

cheers!

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