Re: Limit the size of user updates
See the 2nd example on this page:
http://www.ajaxray.com/blog/2007/11/09/interactive-character-limit-for-textarea-using-jquery/
…and view the source of this page:
http://www.ajaxray.com/Examples/charLimit2.html
Just a few lines of javascript added to your page/template and an onkeyup event added to each textarea.
This works just dandy 
To see it in action, log into my site with username:buzzer and pass:123abc456
Check the homepage or any member /activity/ page.
500 char limit is applied to the textarea in post-form.php
