Do you ever watch the bottom left status bar in Fire Fox when a page is loading? I have been noticing amazon.s3 in the loading URLs on sites like Twitter and DropBox. I have also heard of it mentioned it in interviews with developers. So what is Amazon; a book retailer doing on these websites?

Amazon S3 (Simple Storage Service) is a web hosting service that can be used to host files such as images. You wouldn’t host your site here, just assets which would be called into your site.

So why do this? Their data rates are a lot less expensive than many hosts. For example Amazon charges $0.15 per GB per month for the first 50 TB of data transfer downloads (by viewers visiting your site). The Hosting I use allows for 1 TB of transfer and there’s an additional charge if I go over this.

For the average site this would be overkill and a needless expense, but sites like Digg.com that see upwards of 40 million unique visitors a month have to watch every kb that their site makes users download.

It goes to show that Cache can save your site money!

It seems to happen all too often, some Div is being uncooperative and I spend a handful of minute trying to reign it in. When I was in college the only CSS I learned was the colouring of scroll bars in IE6; so positioning for me has been pretty much self-taught and in times of trouble I often resort to some trial and error. Today I finally took the time to get the definitive answers about positioning and found this excellent post http://www.barelyfitz.com/screencast/html-training/css/positioning/