How do I generate Geo Data for EXIF Meta Data with my Canon SD900?

I wanted to use my existing camera Canon SD900 to generate EXIF Meta Data for Geo Location. I was reading online information that told me there are several external devices that will let me generate GPS locations. I am trying to produce this data for use with panoramio.com so I can upload the image to google earth without having to pin point the location. Please let me know if there is anyone out there who can guide me with this. Thank you.