Hello ,
I need to capture an Image with "Arduino Mega 2560" and then send this Image to my PC via xBee.
1 - The image quality can be low not Hi-resolution.
2 - The Camera can be
I- A USB ordinary web Cam
II- CMOS Camera Module - 640x480. found on sparkfun.com
III- Or LinkSprite camera module found also on sparkfun.com
I'm new to Arduino so , please write more details ,
Thanks. 
HI, and thanks for replaying
How big will the image be?
A 640x480 resolution image , the size is range 150KB to 200KB.
How much memory do you have available on Arduino? Even a Mega 2560?
Mega 2560 has 4KB EEPROM , 256KB Flash ROM , but I can use an external EEPROM.
Do you see a problem there?
the problems are [the title]:
1-How to capture image with Arduino with any type of the cameras specified earlier.??
2- if , so and if I managed to store it on the Arduino memory , how to transfer such image
with Xbee.??
What is the data throughput of the xBee?
xbee 1mW module can transfer 250kbps Max data rate with range of 300ft (100m) range.
How long will it take you to send one image?
not so long , less than 1 minute
Is that fast enough for whatever it is (undisclosed) that you are trying to do?
as soon as the image arrives at my PC , the PC will start processing the image,
it needs not to be so slow and a very high speed is not mandatory .
I chose Xbee because it is widely supported .
any questions I need to ask my self ?? 
EEPROM?
That as a small life cycle and is VERY slow to write?
So you have 2Kb of RAM in the uno/duemilanove, that isnt enought to save the image, and stream the image may be difficult, or impossible.
Why dont you just buy a cheap 10$ webcam and connect it to the pc?
Hello Senso, thanks for your replay
I'm building a mobile robot that will hold a camera on top of it , and at some time dt the robot will capture an image and send it back to my PC for processing.
so that I'm not using a camera attached to my PC ,
and the robot is essential part of my project as I also need some information obtained by encoders that will be sent also to the pc,
but I can sent the encoder data first then sending the image, it really doesn't matter , I only needed this data delivered to my PC at any order.
you can also look into the zipit z2. some nice people ported several linux distributions to it, and it has usb host and a native serial port. you could use the serial port to talk to the arduino and use the usb to stream from a webcam with mplayer or a custom program.
@KE7GKP , thanks for your replay
There are wireless "security" cameras
I think it is a very good Idea , and simple also , I think I'll use it
@weirdo557, thanks for your help ,
but I'm using a PC because the project needs an intensive processing capabilities and without extra coast of buying a new embedded solution.
Maybe you could think about saving your picture on a SDCard. SDshield arent that expensive. But i see were you want to go whit this. minise the number of sending device to the minimum.