Gary Price reports that "Google" is now officially a verb in the Oxford English Dictionary. Google already is a verb in some other dictionaries, but the Oxford English Dictionary (OED) is considered the most authoritative dictionary of the English language. You can see the OED's latest editions for June 2006 here, do a control F (find) for the word "Google."
Google as a verb is defined in the dictionary as;
intr. To use the Google search engine to find information on the Internet. trans. To search for information about (a person or thing) using the Google search engine.