Not sure if this will fit on ur *ist DS but I highly recommend extension rings such as these
http://cgi.ebay.com.au/Extension-Tub...QQcmdZViewItem
I have found the best way to use them is use a zoom lens and the zoom becomes the focus....you need to try it to understand what i mean. Extension rings or tubes for cameras basically mean that you can focus on things that are 1cm away etc.
my 2c worth
Daniel