What is it?
A History of Communications is the pet project of Nathan Shedroff, who apparently has not only a lot of time on his hands (the current version took him close to five years to put together), but a lot of patience. The project is an ongoing attempt to chronicle human advancements in methods of communication from paleolithic writings to cell phones.
Why is it cool?
Why isn't it cool? If you've ever wondered just how we've advanced over the thousands of years we've been writing and talking, then this enormous chronology puts everything together for you. You can now see where the intersection between the creation of the Internet and the evolution of the computer is. The only downside as of now is that the timeline is incomplete. It's extensive, but missing everything that occurred after 1998 and small bits and pieces here or there between what Nathan already has laid out. But, that's really sort of irrelevant at this point, because at five years of work, this list is extensive enough to deserve a good look.
So, go check it out and satisfy your historical curiosity (he also has a whole bunch of other strange stuff on his site, in case you're interesting in poking around).