The latest PLoS ONE has an interesting article on subsurface bacterial contamination in Archaean stromatolites:
Gérard et al. 2009. Modern Subsurface Bacteria in Pristine 2.7 Ga-Old Fossil Stromatolite Drillcore Samples from the Fortescue Group, Western Australia. PLoS ONE 4(4): e5298. doi:10.1371/journal.pone.0005298
I suppose creationists could spin this any number of different ways. I just think it's neat that life seems to be pretty much everywhere on this planet. When I was in grad school, I thought extremophiles were pretty cool. Organisms that can live in high salt conditions, boiling water, or the bottom of the ocean seemed pretty interesting. Now we're finding things that live inside rocks.
Life permeates creation. There's something very right about that.