This answer is no longer relevant. Please see other posts below for more up-to-date jQuery $.ready() impacts. This post is over 3 years old.
See: http://jsperf.com/docready/11
The answer is no! You can litter them as much as you want (note the
word litter). They just become a queue of events that are called when
the ready event is triggered.http://www.learningjquery.com/2006/09/multiple-document-ready