If you'd like to make some guitar string flowers of your own, Julia has a great DIY tutorial up on Candoodles, and the materials are incredibly simple: wire cutters, 1 thick guitar string, 3 thin guitar strings, and craft/binding wire. That's it!
If you are more interested in purchasing a string flower, Julia's online shop Stringcycle is dedicated to beautiful items made from reused instrument strings, and her repertoire is quite impressive, spanning jewelry to flowers to home decor. She finds her strings via instrument repair shops and musician friends, which got me thinking about all the musician friends I have and all the strings they may be breaking...
Head on over to Candoodles for the full tutorial.