Mipmapping (a form of LOD) renders different-resolution images (textures) at various distances from the camera, but up close a texture still appears blurry. I have a way to fix this, in theory, by automatically tiling the texture relative to how close the camera is so the image looks more detailed and sharper.
If done correctly, texture tiling shouldn't, in theory, even be noticeable since 1x1 tiling (at full texture resolution) will occur to fit as much of the camera view as possible. This would probably be easiest on the terrain since its texture(s) tend to be the most blurry up close (since it is a very large mesh) but any polygonal surface's UV coordinates could be altered on-the-fly.
I don't think this can be simulated in SL with one of the LSL camera functions but if someone else wants to give it a shot, go for it.