I tried this in the hardware forum and didn't get any response.
I'd like to start geo-tagging my images so I have a record of where they were taken. Neither my 5D2 nor 7D have this built in, so I would need to consider a dedicated piece of equipment for this. There seem to be a number of options available, but nothing really stands from the pack. I'd be interested to hear how others are doing this, and what they like or don't like about it.