Yahoo announced a month ago that it was pulling the plug on GeoCities, one of the Web's first free web-hosting services. There doesn't appear to be any plan to migrate the thousands (millions?) of websites this will affect to other services. If you don't act by the end of the summer, you're Geocities website will disappear.
That is unless the Internet Archive has grabbed a copy, but they aren't likely to have many pages from each Geocities website archived. I've been conversing with someone who lost a backup of her Geocities website years ago, and IA only had a handful of pages archived. This is likely going to be a recurring story in the years ahead.
My first website was on Geocities. In fact, that's how I first learned how to use HTML in 1997. I'm so embarrased by that first website that I'm keeping the address a secret. I fear the day the Internet Archive's Wayback Machine has full-text search, because someone's going to pull it up and post it on Facebook or something. That's one stream of bites I'm not afraid of losing.