LCDs are often used in microcontroller projects. Most used are these green character displays with two or more rows to display menus, status or debug messages. With mass production of mobile phones, color LCDs get that cheap, that they can be used as replacement.
http://tinkerlog.com/2008/06/14/flickr-images-on-a-nokia-lcd/
This will give you 36x optical zoom on your cell just because of the + the zoom of the lens you may use. It is strongly recomended to use a prime lens for easier calibrating the focal distance.
http://www.c-h-a-o-s.com/2007/06/01/nokia-6280-with-slr-optics/
At some point, just about everyone manages to mess up their precious electronics. In this case, someone (not me) somehow managed to totally demolish the mini USB port in their new Motorola cell phone. Surface mount repairs can be challenging without some serious tools, but it is possible to replace parts without a re-work station. This is how to do it with some fairly inexpensive tools.
http://www.hackaday.com/2007/11/08/how-to-replace-a-mini-usb-port-on-your-cellphone/
A self-tuning, wide-bandwidth portable RF jammer. The device is lightweight and small for easy camoflauging: it is the size of a pack of cigarettes. An internal lithium-ion battery provides up to 2 hours of jamming (two bands, such as cell) or 4 hours (single band, such as cordless phone, GPS, WiFi, bluetooth, etc).
http://www.ladyada.net/make/wavebubble/
I recently scratched my Nokia E61 quite badly. In order to change the cover of my Nokia E61 I had to take it apart. Here is how.
http://blog.petralli.net/2006/08/08/taking-apart-a-nokia-e61/
After removing the battery and the battery cover, you will see two clips at the bottom of the phone. Use a tool of your choice to push the front cover of the phone awayfrom the main body.
http://www.fonegrabber.com/about/replace-n70-faceplate/
If your camera phone do not have an USB jack and still you need to transfer pictures to your PC from your phone, then you can add an USB port to your phone. Here is how for Samsung A620 or VGA1000.
http://computerguru365.blogspot.com/2006/10/add-usb-port-to-your-cell-phone.html
Turn your standard phone into a way to make free Skype calls to landline or mobile phones — in both the US and Canada.
http://www.quepublishing.com/articles/article.asp?p=482671&rl=1
You can either punch in standard 4-conductor telephone cable into the jack or you can use Cat5e and then when you connect it to your phone junction box you can connect the colors from the cat5 to the colors listed here.
http://www.mavromatic.com/archives/000560
This will show you how you can take a single Cat5e cable and turn it into both an ethernet jack capable of 10/100Mbps and a two line phone jack.
http://www.mavromatic.com/archives/000458