My last book was set in L.A. and San Francisco. The one I'm working on now is set in Manhattan. Have I been to these places? Yes. Do I know them well enough to write without research? Heck no.
Enter Google and Youtube. Praise be to the Internets--a writer's best friend (and worst enemy, but that's a post for another day).
I was talking with a writer friend the other day and we both agreed we didn't know how we'd do our jobs without it. Whether it's looking up the exact location of a landmark to researching demonology to translating a spell into Sumerian, I could not write my books without easy access to Google. I'm not one of those writers who can insert a place holder when I don't know a detail. Until I find what I need, I'm stuck.
Now, imagine we suddenly had to go back to living without the internet. How would your life (and your writing, if that applies) be different?