GIMP is the GNU Image Manipulation Program. It is a popular open-source image editor, with a interface and features similar to Photoshop. It is a freely distributed piece of software.It works on many operating systems for such tasks as photo retouching, image composition and image authoring. It has many capabilities, It can be used as a simple paint program, an expert quality photo retouching program, an online batch processing system, a mass production image, renderer, an image format converter, etc. Download from their website Here http://www.gimp.org

Serif PhotoPlus For a long time, Serif has given away previous versions of their software to entice users to purchase the current version. Currently you can download a completely free, fully-functional version of PhotoPlus 6. PhotoPlus 6 features an export optimizer, editable text, image slicing and image maps, selection tools, smart shapes, third-party plug-in support, red-eye removal tool, and photo enhancement tools. PhotoPlus 6 works on Windows 95, 98, 98 SE, 2000, NT4, and XP. Download from their website Here http://www.freeserifsoftware.com/software/PhotoPlus/default.asp

PIXresizer is a photo resizing program to easily create web and e-mail friendly versions of your images with reduced file sizes.The reduced files are saved in a different folder, so your original images are not altered at all. PIXresizer offers several different resizing methods to choose from and can automatically recognize image sizes to calculate the best fit. In addition, it can convert between image formats (JPEG, GIF, BMP, PNG and TIFF), rotate images, convert to grayscale and resize multiple images in batch mode. A great companion for webmasters and digital photographers.
Download from their website Here http://bluefive.pair.com/pixresizer.htm

Picasa is a free software download from Google that helps you:. Locate and organize all the photos on your computer. Find the pictures you forgot you had, Move and re-name pictures from inside Picasa, Make an album, Password-protect collections, Basic Fixes, Amazing effects, Write captions that stay with the picture, Zoom. Pan. Tilt. Get the angle you intended. Download from their website Here http://picasa.google.com/features/index.html

Paint.NET is a free image and photo manipulation software for Windows 2000, XP, Vista, or Server 2003. Paint.NET started development at Washington State University with additional help from Microsoft, and continues to be updated and maintained by some of the alumni that originally worked on it. Paint.NET features layers, painting and drawing tools, special effects, unlimited undo history, and levels adjustments. Paint.NET is completely free, and the source code is also available for free. Download from their website Here http://www.getpaint.net/

Ultimate Paint is available in both shareware and freeware versions for image creation, viewing, and manipulation. It has been designed to be fast and compact, and if you're familiar with the old Deluxe Paint program from Electronic Arts, Ultimate Paint is said to be very similar. The freeware version is an older release of the full-featured shareware product. Download from their website Here http://www.ultimatepaint.com/