I suggest using software that supports the EXIF standard - that way data you add to photos is preserved with the photo. All photo album software recognizes EXIF data. EXIF is pretty limited in what it can store, however. There is a standard called IPTC that goes even farther. And an emerging standard supported by Adobe called XMP. There’s an excellent program called iTag (www.itagsoftware.com) that will add this data to your photos. Here’s an email I received from the author of iTag:

Hi Leo,
I’m the author of iTag

I thought I’d write a quick email to give you a quick low down on tagging your jpegs…so here it is.

There are 3 main headers one can use for metadata in jpegs - EXIF (as you mentioned), IPTC and XMP. Hopefully by the end you will have seen the light and will stop tagging your photos in Flickr and start using IPTC instead :)

EXIF

As you know - populated by the camera and contains mostly properties about how the image was taken - whether flash was on or off, exposure time etc. One thing that I find pretty cool is that EXIF can also store GPS coordinates…so you can store not only the time your photo was takenbut also exactly where it was taken.(Using a GPS with logging and marrying the timestamps of photo and GPS
logs makes this a breeze)

IPTC

This has been in use for many years by news organisations. IPTC has many fields including Copyright, Keywords, Caption, Caption Writer, Headline, City, Country and a few more. The news organisations invented IPTC headers for the same reason you and I need it today - they had so much digital assets that they needed a way to track them and to find them for say - pulling a ‘file photo’ when some news event happens.

I’m not sure when but consumers must have then started repurposing IPTC for their own use. I actually had an email from an iTag user this week who has been tagging his photos with IPTC for 5 years. There are now quite a few applications that can read and write IPTC headers in a jpeg. A small problem is that there are so many IPTC fields and they are very news orientated that its not always clear
which field should be used to store the photo caption, keywords etc - hence the ‘compatibility’ page on my site. There seems to a bit of a defacto standard though and iTag is built to be Flickr compatible…so you tag your photos once in iTag, upload
them to Flickr and voila, your photos in Flickr are already tagged.

XMP
---
There are some limitations with IPTC - keyword length limitations, foreign language support (eg: Chinese characters) etc and so Adobe are now pushing a newer standard - XMP - which is based on XML and is much more flexible (as opposed to the rigid, news orientated fields of IPTC). I believe all of Adobe’s products now support XMP - and as an indicator of the strength of the standard - Windows Vista supports XMP via it’s Photo Gallery. Other applications are a little bit slower in taking up XMP (including iTag).

So I hope that helps. It really is better to add all of your metadata to your jpeg files and then upload to Flickr because so many other apps can also use the data then. Also you won’t be lost if Yahoo tanks and takes Flickr with it (I’m sure its safe as houses, but a lifetime of photo tagging is a lot to bet on Flickr hanging around :)

cheers
iTagger

PS: I’m a long time listener to TWIT & Security Now (and FLOSS too although it seems on hiatus at the moment) - keep up the great work!