Agent Kristin has a post on her blog Pub Rants about the importance of an author having a Web site:

I ended up chatting with a B&N book buyer. She said that the most important tool an author could have is a website.

And I agree. The buyers do actually look at author websites and potentially use them for their internet marketing.

She also has some excellent tips about how authors should get creative with their Web sites. Go read the post.