someone help me understand the usefulness of these items? is the key cles supposed to substitute for a keychain? and why a pochette? is that just a fancy cosmetics bag? i see women going nuts on the forums for these items (from all the designers) and i don't have any of these b/c i don't 'get' what they are for. i see some people with 4 or 5 of these pochettes in their single handbag?! what goes in them? and why not just carry a keychain?