3D Noise and Texturing

I'm currently working on Landscape generation using 3D perlin noise. Unfortunately, there seems to be something wrong with my noise or the way I'm sampling it...

But its still pretty cool....

Also, pictured is deferred texturing and lighting, with point light at the camera's position.

Note to Erin: slightly improved texturing by using the glsl functions dFdx and dFdy with textureGrad.