Here are just a few portraits created by Erika Iris Simmons (aka iri5) using nothing but cassette tape ribbon. I love stuff like this in general, but this is particularly great. You can check out more of the Ghost in the Machine on her Flickr page, and it also looks like she's accepting all kinds of donations (tapes, lace & a butterfly net) on her site.
I think my favorite is the Kurt Cobain portrait, but was so happy when I saw Ian Brown in there. Love those Stone Roses.