Sometime in the next 24 hours, Geocities is expected to stop serving webpages forever. For those that don't know what a Geocities is, read on.
In the mid to late 90s, Geocities was the premier free web site service organized into communities. I used to own a Geocities account. Originally it was located at http://www.geocities.com/CapeCanaveral/Cockpit/8423/index2.html, a part of the science and technology community. (Unfortunately this site no longer exists due to an account issue I had in the early 2000s, by no fault of Yahoo's.) I remember the e-mail I received telling me that my quota had been upgraded from 13 MB to 14 MB, and then a couple years later when Yahoo! purchased Geocities. Geocities was not only where I first played with a website over a 28.8k dial-up connection, but it was also the source of the first password I ever used (randomly generated but constructed in an easy-to-remember way), and is actually a password that I still use to this day, albeit usually with variations.
To commemorate the end of Geocities, XKCD modified their website layout to match one that might be seen on a Geocities page; it is also archived here.
We will miss your historical significance, Geocities.