Some Canadian researchers have determined that it takes people 1/20th of a second to make an aesthetic judgement about a web site (news.com article here).

The researchers didn't identify the reasons for liking or disliking a web site, nor why they conditioned the subjects for such a test in the first place, but it does reinforce the fact that first impressions do matter on the web.

I would recommend the following to get past the first blink with customers:

• 5 W's: Make sure to focus on the Who, What, Where, When, and Why on the home page.
  The W's can have multiple meanings and contexts.
  "Who" you are and "What" you do are important. But who your customers are and what you can do for them is even more important.
• No animation or blinking. These are often perceived as advertisements and distract the eyes search for content.
• Familiar "L" navigation. Do not get creative with navigation, such as employing hover-overs to reveal the navigation item.
• High density information links on home page. The customer should feel like "this is the place" to start looking if there are several well categorized links. A high density home page also acts as a true "home" so that is customers ever get lost, they know they can also get back to where they started in just one click.
• Reduced or no images. This is to improve download speed and allow for higher density of links.