Forgive me if this has been asked before (I have searched the forum and the web in general), but can anyone tell me if it is possible to change a texture during the course of an animation?  In other words, I want to start with one texture and at some frame switch it to another.

I can probably accomplish this by rendering the animation twice, once with each texture set, and then compositing the two animations into one.  I would rather just use Poser to create one animation, however. 

 This can be done using a Blender Node with 2 different 2D Image Map textures plugged into it. You also have to click on the little key's in the material room that turns material animation on and off. Then it's simply a matter of changing the strength of one image map to 1 while lowering the strength of the 2nd image map to 0 over the course of the animation.

Great, thanks for the help!

 Anytime.

Quote -  This can be done using a Blender Node with 2 different 2D Image Map textures plugged into it. You also have to click on the little key's in the material room that turns material animation on and off. Then it's simply a matter of changing the strength of one image map to 1 while lowering the strength of the 2nd image map to 0 over the course of the animation.

I agree the blender node is the way to go, but you can save a step by simply animating the blend level of the blender node itself.  When the blend is at 0, Input 1 should be the only source you see, then when it is at 1, Input 2 will become the texture.  This way you only need to animate 1 value.  This will help later on when you start chaining multiple blender nodes to animate multiple textures in sequence

 Yes, that's what I ended up doing.  At first I tried doing this by adjusting the graph, but then I realized I could just set the blend level on my keyframes directly.