Adding arbitrary graphical elements to charts

[schultcd]

All,

We have an existing report that includes a run chart, and we'd like to add call-outs to that chart -- kind of like speech bubbles like you might see in a comic book. We'd liek to be able to place these elements such that they point to certain elements already laid-out by the chart. 

For example, we'd like to draw the reader's attention to a particular point in time. If the chart looks like this:

 

||||+----------------------Jan Feb Mar Apr May Jun

We might want to add something like this:

|         +------------+|         | See this?! ||         +------------+|        /+----------------------Jan Feb Mar Apr May Jun

The callout above points to the "March" portion of the chart.

Can anyone think of any ways to do something like this? It's easy in spreadsheet programs, because you can always just throw boxes and things like that on top of charts. I suspect the JasperReports charting features can't handle anything like this, and maybe not even JFreeChart (which is under the hood, right?). Any ideas for how to maybe even "fake" this effect?

Thanks,

-chris