Conclusion

The use of CSS instead of table layouts or Javascript (or, worse, Flash) makes your website much more accessible, as well as making it easier, tidier, and more maintainable. But bear in mind that you might face problems with some browsers (notably IE6) that don't implement the standards properly.

Make sure you check everything thoroughly on multiple browsers (including lynx, w3m, or another text-only browser) to ensure that your design is still usable if some of the snazzier options don't work properly.

For more examples of just what you can do with CSS, visit the CSS Zen Garden [3], an eye-opening site showing the power of CSS.