Say a development team includes (or makes use of) graphic artists who create all the images that go into a product. Such things include icons, bitmaps, window backgrounds,
Interesting question. I don't have a bunch of experience working directly with designers on a project. When I have, it's been through a contractual sort of agreement where they "delivered" a design. I have done some of my own design work for both web sites and desktop applications, and though I have not used source control in the past, I am in the process of implementing SVN for my own use as I am starting to do some paid freelance work. I intend to utilize version/source control precisely the way I would with source code. It just becomes another folder in the project trunk. The way I have worked without source control is to create an assets folder in which all media files that are equivalents of source code reside. I like to think of Photoshop PSD's as graphics source code while the JPEG output for a web site or otherwise is the compiled version.
In the case of working with designers, which is a distinct possibility I face in the near future, I'd like to make an attempt to have them "check-in" their different versions of their source files on a regular basis. I'll be curious to read what others with some experience will say in response to this.