Can iPad or Some Android Tablet be used like Graphic Tablets (Wacom Bamboo etc.) ?
Wich one is better?
definitely wacom, I have a tablet but the wacom is obviously more suited.
You need a special pen. Google it.
im not sure, but i think that ipads ect dont simulate pressure. if not then its definatly wacom, the pressure simulation (for me) is key.
Yes i saw , Bamboo Stylus. But how important is pressure? Because i will use it only for texturing. Hand paint textures?
FOR EXAMPLE:
http://4.bp.blogspot.com/_-tlxouyqSR4/TFSWxxAu6bI/AAAAAAAAAVk/Y1xcRdzszSg/s1600/Laureen_LaFave_Tex01.jpg
http://dl.dropbox.com/u/448179/GA/GA%20other/D3FUN8.jpg
http://shogun3d.com/images/treasure_chest/treasure_chest_1_900.jpg
The wacom is better of course, that should be obvious.
I consider pressure sensitivity as something really important for texturing, but if you have enough cash, you can get the best of each world: http://www.wacom.com/en/Products/Cintiq/Cintiq24HD.aspx 
(I want one of those 
)
Thexturing is the most important part and pressure is #1 priority.
You will need the wacom for haindpainting for pressure sensing(like realy drawing) and for the far better tools on pc/mac then ios/android
Thanks on answers, i will order wacom!
http://www.wacom.com/en/Products/Intuos/Intuos4Medium.aspx
What about this thing?
My dream is to one day own the 24" Cintiq from Wacom.
But I guess if you are looking at an iPad the 12" model would be considered enough. Still darn expensive at 999, but darnit, that thing is sweeeet!
The cheapest iPad is 499. Thats 16GB with no 3G. The most expensive model is 899. That gets you 64GB and 3G. If you even consider the most expensive model, then i’d go Cintiq for sure (although the iPad does has other uses.)
Ordered bamboo create for beginning. Thank you all
If you want something nice and large and have little cash get a Genius Pensketch 9x12 it’s awesome and has pressure
Too late, i already ordered tablet. I will see later for something better.
The reason number 1 I’d not recomend something like genius is well, it required batteries to power its devices. Wacom/Bamboo is powered from the main drawing surface - this is true also for the wireless tablet they sell. Beyond that, Genius stuff simply wont stand up to practical use, it breaks. The reason Wacom is the standard is because you buy it, and it still works as good as when you bought it, a decade down the road. With the new bamboo tablets being as good (pressure wise) as the wacom gen 3 tablets, no reason to hesitate picking up one of those (bamboo create) if your not able to grab one of the pricier wacom 4’s.
Even pro artists use bamboo. Why spend more when it is perfectly adequate for the job? Some artists do not require 1024 levels and tilt. For most jobs, it really isn’t an improvement over 512 levels without tilt.
Of course if you’re classically trained and doing fine art, its a world of difference. It’s not a major difference for zbrush or texturing however 
I recently got an Intuos4 small tablet. 2048 levels of pressure sensitivty FTW!
I love it, it was a great purchase and it gets the job done
build your own cintqu