You can use some of the GPS handheld units to do it also. I've even read where a cell phone that has GPS can do it. I know that I've read the iphone can do it.
I am looking at getting my husband a GPS geotagging accessory unit for his Nikon D200 and I saw this review on the GP-1 device made by Nikon: http://www.digitalreview.ca/content/Nikon-GP1-D90-GPS-Accessory.shtml
Are there any other options that I should consider that offer a better cost? I don't think he cares too much if it is a third party brand as long as the job gets done.
Any advice much appreciated.