Twitter has a brand new logo! After six years the logo has been simplified.
You can download the new logos from https://twitter.com/logo
On Twitter’s blog Doug Bowman, Creative Director says:
This bird is crafted purely from three sets of overlapping circles — similar to how your networks, interests and ideas connect and intersect with peers and friends. Whether soaring high above the earth to take in a broad view, or flocking with other birds to achieve a common purpose, a bird in flight is the ultimate representation of freedom, hope and limitless possibility.