UCLA Laboratory of NeuroImaging
Research on brain mapping, structure and function, and related imaging technologies.

The Whole Brain Atlas
Excellent MRI views of the normal and diseased human brain. Collaboration of MIT and Harvard Univ.

Flybrain
An online atlas and database of the Drosophila nervous system.

The Virtual Human Brain
Actual human brain dissection images.

"Zoomable" Brain Picture
A set slices from an NMR brain scan, displayed using Javascript so that the user can view them in series by moving the mouse pointer. Non-scientific.

Comparative Mammalian Brain Collections
Univ. of Wisconsin site has images showing the brain's internal architecture of specimens from over 100 mammalian species for studying differences in brain function and evolution.