Basic graphs: something like groups, but where each plot has independent axis?

I am trying to graph weight data for our colony.  We a data frame with
Animal, Weight and Date.  I'd like to display this data a series of simple
xyplots.  We only need to display these plots together, we do not need to
make comparisons between animals.  Each animal has been weighted over a
different time period, so we do not want the same range for each X axis.


Using the following, I can create one plot per animal:

size <- length(unique(data$id))
xyplot(weight ~ date | id,
    data=data,
    #type="o",
    layout=c(1,size),
    xlab="Date",
    ylab="Weight"
    );

However, they share a common X axis.  Is it possible to avoid this?  In
other words, I might want the first animal's plot to extend from
2008-01-01
through 2009-05-04, while the second plot extends from 2007-02-04 through
2010-01-01.

Also, can I introduce more whitespace between each plot?

Thank you for any help.