Remember this? For those too young to remember, it is a rotary dial phone, and I assume many young people wouldn't even know how to use it. To dial a number, you looked up the phone number in a telephone directory (or your little black book), picked up the handset, pushed your finger into the hole corresponding to the digit you wanted to dial, and moved said finger clockwise until it bumped against the metal thingy. After pulling out your finger, the spring-loaded rotary dialer moved back to its original position, and you then proceeded to dial the next digit until you'd done them all. Simple. To place a call you needed a telephone number, of course, just like you need today. Nothing has changed in that respect. I remember knowing most of my friends numbers by heart. Those I didn't know, I had in my little black book, or they were scribbled on a piece of paper somewhere. My friends had one telephone -- the apparatus in their (parents') homes -- and thus exactly one phone number. Thirty years later the situation is quite different. Nobody I know has only one number. Everybody and his uncle has at least an additional mobile phone. And an office number. And perhaps a SIP number. And the greatest problem of all is that I cannot for the life of me remember any of these phone numbers any more, which is due mainly to the fact that numbers change when people change mobile operators (some don't care to retain their existing cell phone number), and numbers change when people relocate. (There are vanity numbers in Germany, but these are quite expensive.) What has also changed, at least for me, is the little black book. Aside from the printout I keep in case of disaster, I store my phone numbers electronically. In Apple's Addressbook app which syncs over nicely to iPhones and devices which have iSync support. And what about other phones in the house? If I look around me, I find we have quite a few phones in this household. One PBX with three DECT phones connected to it. An IP phone in my office. Two iPhones. One BlackBerry. (And an innumerable number of older mobile phones in boxes in the cellar, but those don't count because they aren't used any longer.) All these devices also have built-in directories: the DECT models have their own but they can list numbers on the PBX, though a bit cumbersome. The IP phone has a telephone book. And LDAP access. And XML. If I weren't so stingy, I'd get a cell phone flat rate and just use that. But I am stingy so I tend to use a land line phone to call land lines, so I have to choose the outgoing phone. As such I need my directory on all phones I use. I've solved the problem by throwing large amounts of software at the hardware. Basically it's a mixture of getting my Addressbook into LDAP (ABxLDAP), massaging that into my Fritz!Box, and sucking some of the directory entries out to create a directory for the IP phone. Does it work? Yes. Is it simple? No. Why is it such a mess? Because there are far too many standards: standards for directory systems (LDAP), standards for SIP phones (XCAP), standards for DECT phones, and so on, and so forth. Who knows: some day I may revert to the little black book and ... the rotary dialer. On the iPhone.