is there a way to make an annoucement flash

There used to be. It was called the tag. So many people used it that it was generally considered annoying by the powers that be at Microsoft , so they completely dumped from their Internet Explorer browser.

There all some alternatives but it takes some higher level skills:

1) Make the announcement a gif animation that flashes on and off.

2) Make the announcement in Flash, upload it to File Vault, and embed it.

You can still use the tag today, it's still supported by other browsers. It just won't work in Internet Explorer because Bill Gates seems to know what's best for us. Here's some more information about using the blink tag.

Any interesting FYI: 70% of all Class Creator users use Internet Explorer.