Just spent a couple of hours going through old photos from various fencing events, and snarfing fragments of pictures for mail faces.
This is something that bothers me about email clients. A long time ago, the Bell Labs UNIX Systems supported a program called "faces". This read through your mail inbox, found email from someone like firstname.lastname@example.org, and then it displayed an image to go with that mail, from a file called /faces/com/place/some/fred/face.gif. (Well, it wasn't a gif file then, but you get the idea). If it couldn't find that file, it'd display a default company logo from /faces/com/place/face.gif, or a default icon for commercial entities. There's a large collection of company logos, university logos, country flags, etc. so that you'd see something relevant for pretty much all your mail.
This was a standalone program, too. It had its own window on your screen, rather than being part of the mail client. When new mail came in, the machine'd beep. You'd look at the screen, see the new icon that'd appeared next to all your other incoming mail, and you'd think, "Hmm, mail from Fred again. That can wait," and you'd carry on with your conversation.
The UK UNIX User Group and USENIX used to have Faces sessions; while you were at their conferences, they'd take your photo and add it to the public database under your email address.
It went further. All of the Faces images were 48x48 black-and-white bitmaps. It turns out that it's possible to encode such an image into a line or three of plain ASCII text, in the character set that's not going to confuse mail relays. So there are people who have X-Faces: headers in their email. The header's value looks like junk, but it's actually their image, and if you're running Faces, Faces would decode and display that image when their email came in.
Take a moment to savour that, for a second. You've never met this person before, but you've received mail from them, and it's displayed a photo of who they are, using less than 240 bytes of extra data.
Later, Faces escaped Bell Labs, and was superceded by XFaces, running on Suns and other X Windows UNIX Systems (including Linux). Not only did XFaces add support for more image formats, including colour images, GIFs, etc. but it also included animation, sounds, and other madness. If you were under Sun's PostScript-based NeWS window system, the images didn't even need to be rectangular...
There's a point to all this history lesson, which is: why on earth didn't this catch on in the MS Windows world? I know why the freeware versions didn't, which is that while UNIX systems were easy to write standalone Faces for (read a local plain-text file, or connect to a POP3 server), all the PC-based mail systems were proprietary messes about which it was impossible to get information.
But I don't understand why it hasn't caught on with people like Microsoft. I mean, look: you'll be getting digital cameras in your xmas crackers this year. Associating photos of your friends with the emails you receive from them is a damn cheaper, easier and better than getting full-on video from them (you get to pick the photo, for a start).
So why doesn't it happen?
The only mail client I know of which supports Faces is exmh. Probably the Mozilla mail client (I forget which one that is) does, but I don't know that. Presumably xemacs does, since xemacs supports everything, but I'm not an emacs user. I don't recall seeing any hint of it in OutLook.
And I don't know why.
Sod 'em. Not my problem. Now I've got about ten more sets of photos, and ten more of my friends who'll have mugshots turning up on the screen each time I read an email from them. I'm happy.