Thing four is instant messaging. How did we ever live without such an indispensable tool before the tidal wave of IM programs swept over us in the 1990s? I remember with great fondness how I used to chat with my friends, including EB and Marshwiggle, on ICQ back when it first came out. Then, AIM and MSN Messenger, of course, and eventually the Google Chat client. There was something empowering and delightful about being able to communicate instantaneously in a written format. It also made roleplaying online much easier, but that is a whole different thing to be thankful for. :-)
I am currently on my third job that involves extensive use of instant message clients. My first job that required IM was at the student newspaper where I served as online editor for a single, lonely, enraging academic year when I was a junior. It came in very handy when I had system-related questions for the techies and the former editor... and also when I was just lonely and bored and wanted to chat with a pretty girl while the incredibly buggy scripts ran on my Mac G4.
I dated the woman who would become my wife over IM for almost a year while I was teaching at a mission school near Four Corners between my undergraduate and graduate programs. The mission's phone line was expensive and unreliable, but the Internet uplink was essentially free and hardly every went down. It was a very, very good way to stay close to the woman I loved.
At my most recent two jobs, chat clients have been simply indispensible. I literally could not have done my job without them. When I worked for a news-gathering service based out of Washington D.C., it was four months before I met any of my colleagues in person, although I worked with 5-10 different people every day to get our products put together. Everything we did was via IM. In my current job at the call center, I am able to provide excellent, value-added customer service in real time because of the intraoffice IM client there.
And last but not least, instant messaging is also an excellent medium for bugging people about things that they should be doing without being too confrontational. For instance, Marshwiggle popped me up via intraoffice IM the other day (yes, he works in the same company I do, more or less) and said, "Hello, sirs. I would like one of your two day weeks, please." This was his way of letting me know he had noticed my absence of "things I like" posts during the week after my power went off. If he would have e-mailed me about it, I might not have responded as well as I did to his subtle hints. :-)
There is much more that I could say about IM clients and the communicative genre of instant messages, but I should probably just close this particular topic with a simple reiteration of my original point: IM is a wonderful thing.