What are the uses of cellular phone in picture taking?
Well, it works much like any other digital camera.
The advantages are that it is an all-in-one device, being able to do things other than just taking pictures. Typical disadvantages include lower resolution than standalone cameras. Typical for low-end to mid-range phones is 1.3 to 2 megapixels. Some phones feature as high as 6 megapixels. The higher the number, the better the clarity and ability to see detail.
Other advantages include discretion. While cameras may not be allowed in certain places, rarely are cell phones excluded. Voila! A way to dodge the rules! Also, pictures may be taken without the knowledge of the subject, since most phones don't have a flash and any shutter sound effect can be muted.
If for nothing else, you can take pictures of everyone in your phonebook so that when they call, their picture pops up on the screen!