Also, regardless of whether it works or not, don't let it affect you. I know some really brilliant people who couldn't get into google, but are masterful coders.
So I'll let you know...
The best tip I can give you is to expect some relatively basic CompSci questions, but ones that might catch you off guard if you're not from a CompSci background. Examples being things like finding a value in an ordered list when you don't have direct access to the data set (just a method call to get one item by its index), and don't know how big it is.
Try not to go for the easiest answer (like incrementally pulling every item in the dataset until you get the one you want) first, try to solve the problem the "right way" - even if it takes a bit longer.
Other than that, relax - Interviews are for both the employer and the candidate, it's not an interrogation.
Good luck! :D
Check out Steve Yegge's blog post about interviews if you haven't already: http://steve-yegge.blogspot.com.au/2008/03/get-that-job-at-g...
"Go confidently in the direction of your dreams. Live the life you've imagined." ― Henry David Thoreau