Image Compress websites

punypng

http://www.gracepointafterfive.com/punypng/

PunyPNG is a free website optimization tool that dramatically
reduces the file size of your images without any loss of quality.

 

Smush.it™

http://developer.yahoo.com/yslow/smushit/

Image optimization is an art few have mastered. Useful image editing tools exist that allow images to be edited to reduce their file size while retaining image quality. Using these tools is a good start for optimizing images, but more can be done using advanced tools like Smush.it.

 

OptiPNG: Advanced PNG Optimizer

http://optipng.sourceforge.net/

OptiPNG is a PNG optimizer that recompresses image files to a smaller size, without losing any information. This program also converts external formats (BMP, GIF, PNM and TIFF) to optimized PNG, and performs PNG integrity checks and corrections.