I've put together a quick website that helped me when I was working on a new intro video for my cabinet.
http://www.push-a-button.com/retrovision/ allows you to convert a sprite you've isolated to a 2D SVG file (for use in Inkscape, Illustrator or other vector drawing applications - handy for making marquees or side-art), and also to 3D object files that can be imported into Blender, 3D Studio, Lightwave or other 3D graphics programs to create videos.
The process is pretty straight-forward...
a) Take a screenshot from your game, or simply download an existing screenshot (retrocpu is pretty good for this, they have very clean, sharp screenshots of MAME games)
b) Open it in Photoshop / Paint / Gimp or your image editor of choice.
c) Crop your image around the sprite you are interested in. Hold 'shift' when selecting the region to crop, since it's best to have a square image.
d) Make sure the background is all one colour and that the top-left of your image contains the background colour.
e) Save the image as a PNG file and upload it to
http://www.push-a-button.com/retrovision/Then download any one of the various formats you've created. Previews are available of both the SVG and the 3D models.
