A little nicety I noticed when getting info on a disk image on my desktop this morning. There is now a "Where from:" field under More Info when I download a file from Safari. I don't know if this was there in Panther but I know utilities exist to add this feature. Just a note though, if Safari automatically opens the fie to say, mount the image or unzip a zip, then the resuliting folder or file does not have the where from field.
[robg adds: This field is used by Spotlight; the 'raw' name of the field is kMDItemWhereFroms, which you can see in the list of all possible Spotlight metadata (mdimport -A).]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20050517161414507