Streaming textures using pixel buffer objects:

const int texWidth = 256;
const int texHeight = 256;
const int texsize = texWidth * texHeight * 4;
void *pboMemory, *texData;

// Define texture level zero (without an image); notice the
// explicit bind to the zero pixel unpack buffer object so that
// pass NULL for the image data leaves the texture image
// unspecified.
glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, 0);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, texWidth, texHeight, 0,
GL_BGRA, GL_UNSIGNED_BYTE, NULL);

// Create and bind texture image buffer object
glGenBuffers(1, &texBuffer);
glBindBuffer(GL_PIXEL_UNPACK_BUFFER_ARB, texBuffer);

// Setup texture environment
...

texData = getNextImage();

while (texData) {

// Reset the contents of the texSize-sized buffer object
glBufferData(GL_PIXEL_UNPACK_BUFFER_ARB, texSize, NULL,
GL_STREAM_DRAW);

// Map the texture image buffer (the contents of which
// are undefined due to the previous glBufferData)
pboMemory = glMapBuffer(GL_PIXEL_UNPACK_BUFFER_ARB,
GL_WRITE_ONLY);

// Modify (sub-)buffer data
memcpy(pboMemory, texData, texsize);

// Unmap the texture image buffer
glUnmapBuffer(GL_PIXEL_UNPACK_BUFFER_ARB);

// Update (sub-)teximage from texture image buffer
glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, texWidth, texHeight,
GL_BGRA, GL_UNSIGNED_BYTE, BUFFER_OFFSET(0));

// Draw textured geometry
glBegin(GL_QUADS);
...
glEnd();

texData = getNextImage();
}