What next (newbie Q)

I've probably jumped in out out my depth, but here goes...

I completed the Macromedia tutorial Data Tutorials >> XML Tutorial: Timesheet

Here's the result......

http://scraf.com/timesheet/Timesheet.swf

it loads this xml data.....

http://scraf.com/timesheet/data.xml

...and is editable (show updates)

OK, fine. My question is what can I actually do with the result? As in, is it possible to alter the existing xml text file, or should I be looking at using php to alter an xml database or something?

TIA

An example of a result.....

PHP Code:

<?xml version="1.0"?><xupdate:modifications version="1.0" xmlns:xupdate="http://www.xmldb.org/xupdate" transID="IID77769553987:Wed Feb 25 09:27:18 GMT+0100 2004"><xupdate:update select="/datapacket/row[@id='1' ]/@duration" opID="IID62218299042">8</xupdate:update></xupdate:modifications>