character LCDs being used in electronics VS Mobile LCDs

Hi, I feel that the cost of character LCDs being sold in sparkfun and other stores are costly. I can get the old mobile LCDs / calculator LCDs at very cheap prices.. Infact, many cheap new mobiles itself cost less than those LCDs being sold in electronic stores.

1. Is it easy to use a mobile LCD instead of character LCDs?

Character LCDs / those being generally used in electronic projects:
http://www.sparkfun.com/products/710
http://www.sparkfun.com/categories/76?page=all

Mobile LCDs:
monochrome - 96x65 pixels - http://www.fonearena.com/nokia-1100_41.html
Monochrome - 96 x 68 pixels, 1.36 inches (~87 ppi pixel density) - http://www.univercell.in/buy/Nokia/1280

2. LCDs being used in cheap calculators are same as the one being sold in sparkfun and other stores?
Sparkfun: http://www.sparkfun.com/products/9053
calculator LCD: http://imshopping.rediff.com/imgsho.../l/LC110._citizen-pocket-calculator-lc110.jpg

Please share your thoughts. Thank you !

LCDs without a controller require an AC waveform; there are some microcontrollers with an appropriate interface, or there are dedicated LCD controllers.
Color displays need a high-speed refresh, and would require a lot of RAM, a lot of interface pins and high speed microcontroller. For this reason,
it is often easier to use a dedicated controller IC or programmable logic and RAM to drive them.
The displays with built-in controllers are more expensive naturally (but are sometimes available for $10-$15). If you buy a cheap ($1-3) LCD, then it may
not have a controller, and so you need to expend some effort and money in implementing that using the methods mentioned above.
In the fairly-cheap _and_ easy-to-use category are the popular character (text) displays that all use a similar interface (HD44780).
For $10-15 you can find graphic displays with a built-in controller too.