Arcsecond size of the Andromeda Galaxy

[Simfish]

So it's often said that the Andromeda galaxy is much wider than the moon, if you count all of its outer regions as well. Yet, you can clearly see much of the Andromeda's spiral structure in the small region that the visible-to-naked-eye region occupies. So what do the outer regions of it look like? And is there a diagram on a star chart showing how far it stretches?

 

[Chronos]

Andromeda is larger than the full moon to the naked eye.

 

[russ_watters]

This photo is 80 arcmin wide and doesn't quite get all of it: http://www.russsscope.net/images/M31-10-20-09.jpg

There are quite a large number of galaxies that are big enough that they'd be resolvable with the naked eye if they were bright enough.