There are a number of online dissections on the net. Here are some of my favorites:

Cockroach Dissection
Information on dissecting a cockroach. Also contains QuickTime movie clips of the dissection.

Cow's Eye Dissection
Step-by-step instructions, tips, and hints on how to do a dissection of a cow's eye.

More Cow Eye Information

Participate in an online dissection of a Bull frog. Must have Macromedia Flash Player to view this demo.

The Interactive Frog Dissection Tutorial
The title says it all! Dissect a frog without smelling any formaldehyde.

Netfrog: The Interactive Frog Dissection
This one has nice quick time video

Rat Dissection Guide
Covers rat muscular and digestive systems with images from an actual dissection.

Rat Dissection Guide II
Covers rat respiratory, circulatory, and urogenital systems with images from an actual dissection.

Sheep Brain Dissection
A step-by-step guide on how to dissect a brain. Learn about brain anatomy, structure, and function.

Virtual Cat Dissection
Learn about cat external anatomy, skeletal, muscular, respiratory systems and more.

Virtual Fetal Pig Dissection
View a simulated dissection of a fetal pig. You must have Shockwave plug-ins to view animations.

Good dissection slide show of fetal pig

More Fetal Pig

Virtual Mouse Necropsy
Instructional guide for the dissection of a mouse. Includes detailed diagrams.

More Online Dissections Information

For more information on online dissections see:

Virtual Frog Anatomy
Guide for identifying anatomical structures in the male and female frog. Images are labeled.

Virtual Frog Dissection Quiz
Think you know all there is to know about frog dissections? This quiz is designed to help you identify internal and external structures in the male and female frog.

University at Buffalo: Dissections Online
Contains a large collection of animal dissection information.