Hello i have to do a mini project where i should implement both electronics and mechanics. So my theme is to design a mini project to facilitate life of elderly people...can somebody share some topics or ideas on it. I'm new to arduino and i would like some guidance. thank you 
An automatic door opener. With a pir sensor and a motor to open the door.
A device to walk up straight, with a detector high on someone his/her back that makes a sound when not walking up right.
A walking stick that has a TV remote inside.
A computer with skype that turns on and swings in front of a person laying on bed at a voice command.
Sensors in the floor that detect a person or wheelchair and determines the direction, and automatically opens the bathroom or toilet door.
A device that automatically cooks something or makes coffee with a single button.
An automatic water system for plants or for a green wall with moss.
You can have a look at the Playground section : http://playground.arduino.cc/
Click on the left on "Interfacing with hardware" and "User code library". Explore those sections, there should be perhaps hundred usable ideas for you.
ask the elderly people what they think will make there life easy.
remote that are hard to lose for what ever electronic equipment they use would be a help.
if you can come up with a remote that can be plug and play a receiver that can be spliced in easily with a remote that can be easyly changed for what ever its connected to
automatic curtains
don't forget the pill's device
memory trainer
Sorry for the stereotype image of the Elderly 