Here is a really bad example of FLASH:
I think that says it all. Remember, users are coming to your website for information, not for "cool" effects or nitfy presentations. There is a use for new technology, but not at the expense of getting information quickly.
• Don't forget the purpose of your site is to inform, not to entertain
• Using newer technology can alienate visitors due to their outdated technology.
• Newer technology means more upkeep on your site--think about return visitors.