Every week there's a new hot thing on the web, making it almost impossible to catch up...but if you want to reach a wider audience, try to wait until something is generally accepted by users and developers. Somebody needs to push the envelope with testing new products, but this has to be balanced by the willingness of your visitors to download components just to view your site (or their inability to do so, preventing them from seeing what you have to offer). Some examples of this are:

• java applets
• activex controls
• shockwave objects
• tools that require plug-ins
• specialized document formats

This doesn't mean you have to avoid these things, as there is a time and place for everything (as well as a value for being on the forefront)...but be aware that not everyone will be able to enjoy the extended benefits of these features, so use them wisely, and ensure that there is an alternative for people who don't want the 'extras'. Keep in mind that there are always different ways of achieving an end result.