No matter, what you are —a “blogger, web developer, programmer, graphic artist, or regular Mac user, you may regularly be using PNG files. PNG is a great format. It's lossless, patent-free, open, and supported by all sorts of stuff. It's great for screenshots, line drawings, and anything that needs to look good. Unfortunately, many programs which save to PNG format do a horrible job of it. Adobe Photoshop is one of the worst offenders, creating PNG files many times the size they should be.
To overcome all these problems paramac has developed a tool called Ping! To use it, simply drop a PNG file on it. Ping will then optimize the file, often reducing its size to a mere fraction of the original.
Ping works by optimizing a variety of aspects of the PNG format (palette, compression parameters, IDAT chunks, etc.) but it does not remove any image information from the file. Since PNG is a lossless format, it certainly wouldn't make sense to throw away information.