FILEminimizer Pictures - FILEminimizer Pictures compresses JPEG photos, TIFF, BMP and PNG images and pictures by up to 98%.
Imagify - Optimize and resize images online and through your CMS.
Caesium Image Compressor - Compress your pictures up to 90% without visible quality loss.
Cloudinary - Cloudinary is a cloud-based service for hosting videos and images designed specifically with the needs of web and mobile developers in mind.
Shrink O'Matic - Shrink O'Matic is an AIR application to easily (batch) resize (shrink) images.
TinyPNG - Make your website faster and save bandwidth. TinyPNG optimizes your PNG images by 50-80% while preserving full transparency!