We have seen number of web tools to create cool mosaic images from your personal photos like here and here. Checkout Twitter mosaic to create mosaic of Twitter avatar photos of Twitter friends and followers for your Twitter account.
To get started, enter your Twitter username and then select among ‘friends’ and ‘followers’ and then click on GO. Your Twitter mosaic will appear very soon which can be embedded to any website or blog using provided embed code. You can even order shirt, mug, card and bag with your Twitter account mosaic – checkout Twitter Mosaic.