As of today (26th October 2009) Yahoo Geocities is no more. I only found out this information a little while ago, otherwise I would have posted it before.
GeoCities is not being decommissioned — it's being deleted. That means any data not personally backed up by its owners or readers will not be recoverable, ever.

If anyone has bookmarks/favourites in Geocities then I would urge you to copy and save the information now, it any of it is still available.

Unfortunately I found this out the hard way, and a wonderful site on building a micrometer vernier sextant that I had bookmarked some years back - with the intention of attempting this one day - has now gone forever.
The internet archive/wayback machine does not have a full copy either.


Edit: More internet weirdness - this particular (sextant) site had disappeared forever this morning, and now it's back up again. At least |I can now go and grab the files I want.
Confused Peter