My 4-year-old son was playing video games with his big sister tonight, so I took this opportunity to play around in Illustrator CS3.

This is the start of a cellphone illustration. Fig.1a is the preview mode and Fig. 1b is the outline view.
Fig.1a

Fig.1b

Fig.2a

Fig.2b

In Fig.2 I have added the keypad and numbers along with the top slider. All the shading that you see is with careful manipulations of the gradient slider palette.

And ta-da! The final illustration. Total creation time: Approximately 40 mins

I used one drop shadow effect, but otherwise the phone is completed made up of gradients.

Below is the outline mode of the illustration.