I created a facebook group a while back about'interactive technology.' While it hasn't gathered much steam, it does seem to be attracting a few eyes now and then:

http://www.facebook.com/group.php?gid=62018403559

Usually found on the steering wheel of a car positioned on the side of the steering wheel closest to the door. 

A simple and intuitive way to control the turning indicator lights of a car which first appeared in the 50s/60s.

If there was no stalk, imagine having to use dip switches/levers on the dashboard to control each turning indicator light with each dip switch/lever on opposite ends of the dashboard. Manually switching the indicator on and off would be a nightmare when one has to make multiple turns  since the driver would have had to take their hands off the steering wheel to activate the the light before they were about to attempt a turn, overtake or pull over.

The indicator stalk with its simple up or down motion (and placement to the side of the steering wheel) for activating left or right turn indicator signals makes it easy to signal to other cars that the car being driven is about to move to the left or the right side of the road.

While technically, the indicator stalk is not an interactive product since it cannot be used as a standalone device (it is meant to be used as a part of a vehicle,) the indicator stalk is an example of well implemented interaction design.

Source:

http://www.decisiondrivinguk.com/flashingheadlights.htm

http://twitter.com/

There are blogs and there are twitter accounts.

Twitter is social media messaging to the world. Twitter posts are limited to 140 words and contain no more than test and links.

What twitter lacks in quantity it makes up in distribution and interactive options. Posts can be replied with minimum ease. Your home page on twitter not only displays your own posts but the posts of persons you follow as well (their pages can show your posts if they follow you too) and all one has to do to reply to a message is to hover on the message and click the reply button on the right.

Twitterfox for Firefox and Tweet Deck adds even more immersion to the twitter experience.

First introduced in late 1997 for the Play Station as the Dual Shock Controller

The addition of dual analog thumbsticks added increased control within video games. The addition of forcefeedback made the immersive feel of the games more real. Car crashes (Gran Turismo) could be felt, a helicopter taking off behind the player could not only be heard but felt as well.

http://www.cleartrip.com/

Easiest to use online travel arrangement website in India

Includes air travel, hotel and railway booking

A very efficent interface that requires minimal thought to use.

Produced by Apple

Click Wheel first introduced in the iPod mini brought the iPod to the forefront in interactive innovation. Users no longer had to move their fingers away from the scroll wheel when interacting with the device. All actions were within an inch of the user at any time.

Excellent ability for single handed users to use.