Howzit
Say I have 4 textures and I have a quad. What I want to do is put all 4 textures on the same quad at different locations, so it will look like one big picture. How do I do that?
Shot
Hmm… you just take 4 quads 
Or you create an image that contains your four textures and apply it as a texture.
Kev
I want to put them on the same quad.
Or actually, could you multitexture it and use a different set of coordinates for each texture and GL_CLAMP it to the edges?
Kev
That’s what I want to do. How do I do that?
Nehe lesson 22 is about multitexturing.
http://nehe.gamedev.net/data/lessons/lesson.asp?lesson=22
Although it’s about 100 times as difficult to implement as just using 4 quads 
Let me tell you what I want to do.
I’m writing a game that has a scrolling background but the background is different, i.e. think of StarCraft
There was a post a while ago that asked if he should import a huge image or smaller ones.
If I import a huge image it’s going to lag my PC because it will will be about 16000 pixels each way, x, y. If I can make smaller images say of 1024 pixels and then place them where I need them there won’t be such a lot of drain.
Otherwise I have to keep track of where the different quads are.
Assuming you render with an orthographic projection, then tracking the quads is no different the tracking individual images with a 2D API. You can set up the ortho projection so that (0,0) corresponds to the upper left corner of the screen. Then you just handle map drawing the same as you would with a 2D API, but instead of blitting an image you render a textured quad. You’ll need to keep track of which coordinates in the world coordinate system are currently at the upper left corner of the screen, then translate that to an index in a map array (or whatever data structure you use). There’s a wealth of info available on the net showing how to do that.
That is all assuming an ortho projection, but if you are using a perspective projection it could be a bit more complex. Either way, using one big quad with several textures scattered about it is not the way to go.
I’m using glPerspective.
Then I guess now the question is what sort of game are you making? When you said ‘scrolling background’ I assumed it was a 2D game using OpenGL for rendering. Is that the case? Or are you using 3D geometry?
Even if it is a 3D enviroment, you can still use ortho projection to draw the background and switch to perspective to draw your objects on top of it.