PicArtia helps you to create your photo mosaic online for free. It is popular for being fast, easy and free!
http://beta.picartia.com/
Photo Mosaics are great gifts for friends, family members and even yours. Most of our users would print it in large size and use it as a poster for their office or room wall. Some users even use it in their blogs, websites or post it as an online gift to their friends on different occasions like school gatherings or birthdays.