I love using Adobe Photoshop CS5.
It’s very useful to use Photoshop because we can use it to draw beautiful drawings and edit pictures.
We can add lighting to the picture too.

We can also cut the picture in a shape that we want.
You can also draw grass using Photoshop.

We can also use Pattern Stamp Tool.
Pattern Stamp Tool is a brush that can paint a multi colour line, for example:

We also can turn our picture into 3D; for example:

We can use Photoshop CS5 for lots of other things other than pattern stamp, grass, cutting a picture.
Anyway I haven’t learn them yet, but all I know is there are more than 10 things that we can do using Photoshop CS5.