I always use tables to format elements on my web pages. I suspect that there are many others, more efficient ways to do that.

For example, a bond of xml and xsl is used actively in the J2EE applications world to format elements on the web pages.

But in my opinion, one of main reason to choose either of formatting approaches is a target of your project.

If you produce some simple site it'll be enough to format elements using tables. If you develop some enterprice application you should begin to think about more complicated solution