How download images?

[eluser]brigham[/eluser]
I'm downloading images from the web onto my server.
Can one do this in CI?

Specifically,
1. the user types in some search terms,
2. we do the search on Google images,
3. we show the user the thumbnails,
4. the user clicks on an image and we download it from the web onto our local filesystem (it becomes the user's avatar.)

...I'm not sure how to do #4 in CI

Thanks,
Brigham