I recently did something similar for more general elements as a jquery plugin: http://jquerypulsate.kilianvalkhof.com/ http://jquerypulsate.kilianvalkhof.com/ i

I recently did something similar for more general elements as a jquery plugin: http://jquerypulsate.kilianvalkhof.com/ http://jquerypulsate.kilianvalkhof.com/ it uses the outline-offset css property, which doesn't seem that well known but seems quite useful too.