How do you make 360 degree skies? By that, I mean skies that go all around the map like in Area 53. I tried having all the surfaces in my skybox have the +sky material, but that didn't work (the sky only assigned to the top and side faces. I also tried creating a star texture and putting that as the ground with the +sky on the sides and top. That just looked like a floating star plane.

The sky should assign to all +sky faces.
Some or all of the stock skys are made from a half sphere, i would imagine that is why the bottom half looks black. it does show as black right?
If you can see an obvious line where the bottom of the sky ends (thats not a material id seam) then i think thats the problem.
Use a different sky, or edit the one you are using.

Oh, thanks. I'll look for some full skies. And yes, half the screen shows up as the sky and the other half is just ugly gray on the default ones.

maybe check the sky from Prime.
I dunno how the map was made, but it may have a full sphere/box sky.
If you cant find one, you could import a sky and change the geometry and bitmaps to suit your needs.
If you cant get that done, post back and ill help ya.

http://www.youtube.com/user/eliteslasher#p/a/u/0/aw_GMZY6PJk
thats easy :)

it does

You just make those settings and use a spiral texture with an alpha.