One of the most disappointing Apple applications I've used is Apple's iWeb because it simply didn't make creating a website as easy and as great as it should be on the Mac.
Shutterbug is an interesting alternative with 80 fully-customizable, free themes, allowing you to create a simple online photo gallery or simple multimedia website with very few clicks.
When you open ShutterBug, there are three tabs on the interface - 'Content', 'Layout', and 'Preview'. Through these, you have a WYSIWYG editor that allow you to build your content in three steps. What I like about Shutterbug is the fact that it gives you far more control over the look of your websites including the masthead, footer and title. The choice of themes is also far greater and overall, you have the power to create a much more advanced site with very little web design knowledge.
It's a shame that Shutterbug doesn't go beyond photo website creation, although it does make editing and publishing images such a pleasure. A super web design app for beginners.