I have never heard of this Picnik before, but after experimenting with it I found it very useful. It is good for editing the size of images that may be too large. One thing I hate is when webpages taken a long time to download because of large images. Therefore by reducing the size of an image the website page can download quicker, subsequently saving a lot of time. This is useful because when a student is researching it can be very time consuming when webpages take a long time to upload and quicker downloads means students will not lose interest.
Using Picnik I was able to manipulate this image. Originally this picsture was 768 by 1024 and by using the resizing and crop tool I was able to reduce it to 98 by 116.I also experimented with the colour tool and changed the colour photo to greyscale. Picnik is a quick and easy way of editing images, and its FREE!