Our new “Share this” button makes it a whole lot easier to share your photos, video, sets and groups. You can click the button and start typing the screen name of one of your contacts – auto-complete will do the rest. Or, you can enter any email address.
You can set a global preference (from “Only you” to “Anyone on Flickr”) on who can use “Share this” and “Send to a friend” via your account page.
More info about the changes to sharing are available in the FAQs, and do some sharing of your own by way of feedback in in this Help