I have started exploring with blur tool in illustrator. Much more time consuming than Photoshop I must say. But I'm satisfied with the results. :)
This illustration is part of icon-a-day.com project.
Follow: Tumblr | Twitter | Behance
Buy Artwork: Society6 | Redbubble
It was mentioned to me that user Kondratieva Anna made similar illustration few years ago. I failed to see it, and rebound it. Here is the link to her awesome illustration.