With NN6+ (Netscape Navigator 6.0+) you can use the blink tags, there name tells you what they do, but in case you haven't caught on yet they make text on your page flash (sweet) the problem is that they only work for NN6+ at this time (Not tryed on Mozzia ForeFox)

Its like this::

Code:
<blink>Text Here</blink>
The <blink> tags wont show up if displayed in IE for anyother browser so you can have it there as a specal feature for NN users...