Well it does if you are designing websites.  The important thing to bear in mind is your audience.  According to this w3schools.com report on browser statistics for January 2008  the  trend is that more and more people have their screen size set to 1024×768 pixels or greater with 48% viewing on 1024×768 and 38% using higher. Only 8% are still using 800×600. The figures for November 2008 from w3counter.com show a similar trend with 41% using 1024×768, 49.02% using higher and only 5.42% using 800×600.

So what is the best width to use for your layout?

For viewing on a 1024×768 resolution or higher, allow about 50 pixels for browser scrollerbars,  this gives you a width of 974.  Round down to 950 or 960 which leaves a small amount of background visible on either side of your design (assuming you centre it on the page).

Your site may not have a whole lot of content and you may prefer the minimalist look with a fixed width of 800 or 850.  You can always add an extra column outside the main content div for advertising.

Using a complimentary colour or repeat pattern on your background can enhance the overall look of the page rather than just having lots of white space either side of your design.

Some designers prefer a ‘liquid’ layout using percentages instead of fixed width, so that the page width fits the viewer’s screen width or a percentage of but this can reduce the control you have over the how your design will ultimately look on various screen sizes.  It can also  result in a really messy looking layout on a very large screen and possible overlapping on a very small one.

Consider the mobile user – or not, it’s up to you.

However, do bear in mind that more and more people are accessing the internet via their mobile device.

Some services have a primarily mobile appeal (location based services, for example).  Some have a primarily mobile appeal but have a complementary desktop aspect (for instance for complex configuration tasks).  Still others have a primarily desktop appeal but a complementary mobile aspect (possibly for alerting).  Finally there will remain some Web applications that have a primarily desktop appeal (lengthy reference material, rich images, for example).

- W3C recommentations

Using media queries to tailor your content to a specific range of output devices will make your site more accessible to mobile users.  A simplier way would be not to design a one-for-all site, but instead make a mobile-friendly alternative that is linked from your main web site.

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