XKCD-inspired frequency-based blinker http://xkcd.com/1331/
Download frequency.js.
Set up your script tags:
<script src="http://code.jquery.com/jquery-1.11.0.min.js"><script>
<script src="/path/to/frequency.js"><script>
Add the attribute data-frequency="<time period in seconds>" to any element that you want to flash:
<span data-frequency="2.71828">This will flash once in 2.71828 seconds.<span>
<span data-frequency="10">This will flash once in 10 seconds.<span>
And we're done!