I extracted these images from my PS2 using the Action Replay MAX to bring them to my PC. I then utilized the PS2 Save Builder to extract my GALLERY.DAT file, and then the GTA: SA Gallery Builder to create the JPEGs you see before you.
The images I present are not spoilers in and of themselves; they're simply scenic shots. If I do take any pictures of something that may be a spoiler, I'll link to it and put in a warning.
The Women of San Andreas - (Potential Spoilers: I took pics of the girlfriends you can meet (as opposed to the two you run into during gameplay) and one of a particulary good looking female ped. This can be added to as time goes on)

A scenic shot of the misty woods on Mount Chiliad.

Picture of a countryside bridge, with the ocean as a backdrop.

An early morning view of a large hill.

Nighttime view of the Mount Chiliad trail.

The Avispa Country Club.

Late morning shot of the ocean.

The countryside of Red County and some local nature.

Nighttime view of the north side of Mount Chiliad.

One of the best, in my opinion: a sunset view of the north side of Mount Chiliad.

The San Fierro countryside enshrouded in a post-rain mist.

The "Regular Tom" geyser in Bone County at sunset.

The "Big Ear" satellite dish at twilight.

The San Fierro skyline at night.
Well, these are just my first batch. If I post any more I'll edit them into here and put an update as a reply.
If anyone else has any screenshots they'd like to share, please do so.