Your site is not rendering correctly in FireFox (v3), and throws errors. I agree with the other comments about too much "stuff" on your home page.

Also, pay attention to where the page folds are for different screen resolutions.

I think you should also go over the different screen items and note how much your site visitors would really care about each item. For example are your "McAfee Secure" and "Buy Safe" icons really that important to hold such a prominent place on the page?

Also, your three black "buttons" across the top-right imply that they can be clicked by their design and labels. i.e. What vare the "Free Accessories" I'll get with my order. What exactly is your "Lowest Price Guarantee"? Is it real or hyperbole? What are the "Hottest Phones of the Season"? I want to click and see them.

There's quite a bit more tweaks to be done, but then, that's why I get paid the big bucks for website usability analysis.