Everybody knows the great image software or Photoshop or free alternative GIMP, but there are some great web applications which you can use to edit images.
Some can be extremely useful for quick changes or for compressions. Compressing image can help speed up your page loading times but still keep the same quality of images.
Here is a list of some of the websites you can use to edit images online.
Phoenix Image Editor
From basic image retouching to complex effects, Phoenix delivers the key features of a desktop image editor with the simplicity and accessibility of a web-based application.
iPiccy makes your photo awesome with many easy to use photo tools. Edit pictures, apply beautiful photo effects, add text and even paint! Enjoy free photo editing online and show your creativity with iPiccy editor!
Rsizr is a Flash application that lets you resize JPG, PNG, and GIF images on your computer. With rsizr, in addition to normal image rescaling and cropping, you can also resize images using a new image resizing algorithm called seam carving (a method of image retargeting) that tries to keep intact areas in your image that are richer in detail.
Cut My Pic
Cut My Pic allows you to upload a picture and crop it to any area you want using a web application.
Image compression that just works PunyPNG is a free website optimization tool that dramatically reduces the file size of your images without any loss of quality.