Is it possible to play animated textures on a polygon like an animated GIF in Oblivion? What about playing a movie on a polygon? Or are movies full screen only like the intro movie? Are menus with pictures possible?

Not sure about the menus, not my field. But on meshes that aren't rigged you can set up a niflipcontroller, these play a sequence of textures like a movie sequence. you can animate the material in max and export them with the civ4 plugin. Or you can set them up solely in nifskope, tbh I don't know which way is easier. They won't play on rigged meshes, and normal maps are not used.

Menus with pictures (or icons) are possible from what I've seen. But they should involve significant XML/UI hackery.

That's what I did with my animated picture frames in my http://www.tesnexus.com/downloads/file.php?id=19058 - I have a few different pictures that can be purchased and placed where you want - 1 has the intro movies flyover of the IC another has the emporer from those movies also.

http://www.youtube.com/watch?v=7PsqcQBJEBg of the first one I made when Spore had just released to give you an idea of them.

They use a NiFlipcontroller as mentioned on a simple rectangle that plays each movie frame for a short time - feel free to reuse the ones from the mod and just replace your clips in place of the current ones if you'd like

This is definitely possible on meshes, but I'm not sure about menus. http://cs.elderscrolls.com/constwiki/index.php/Basic_Animation_Tutorial#Creating_a_Texture_Transform_Controller_animation it has an image illustrating animated textures on meshes - the picture frame and the stones particularly come to mind. I've not fully read the tutorial, but it does seem to have a "Creating a Texture Transform Controller animation" section. Sounds pretty promising

texture transforms aren't flipping textures. Though you could create a large texture, set up in a grid, with each frame in a different grid section, and then use the tranform to move the texture in U/V so that it looks as if its a flip texture. Basicially this is whats happens in fallout3 if you see this effect, Flip controllers aren't supported anymore- the nitexturingproperty only gets minimal use, and as far as my efforts have gone, flips don't crash, but they hang the GECK.

The big problem with texture animations is really the missing normal map(s). It works great for glowing things like fire, but it doesn't work well for regular objects since they're not affected by lighting. An animated texture without emissive color will be solid black plus ambient lighting. You should also keep in mind that a missing normal map means the texture is not affected by fog. That means you will see the object from a large distance even if the rest of the world/interior is covered in fog. If you've ever approached a waterfall or a camp fire while there was foggy weather you know what I mean.

Another reason to use the texture transform method.

I thought texture transforms can't have a normal map either? Tried to make a Dwemer conveyor belt using that method a long time ago. I might be wrong though.

Pretty sure tranforms can. iirc I have done it on a particle system in oblivion. and fallout3 deffinitely can.. or am I making that up. lol

edit: ah probably not in f3. I remember what I did now.. So not sure about oblivion though. I give it 50/50 chance

So your actually displaying a .bik movie file on a polygon in that mod right? Does anyone know if its possible to download a you tube video and covert it to a bik format?

As mentioned JD used a flipping texture. Not a bik.

No I first converted the bik to AVI Using http://www.radgametools.com/bnkdown.htm (just click where it says Rad Video Tools to download) and then exported the seperate frames from the AVI using Adobe Image Ready (it can import the .avi and then export a timeline as frames) and then converted those to .dds using photoshop.

As far as converting a youtube video to .bik the rad video tools can do that I believe !