During my time at Laboratory for Applied Research in Electronics (LARE), I worked on creating an eco-system of electronic widgets for educational/development use.
We called it the UNIBlocks.
Although LARE is no longer operational, you can still get some of these or similar widgets from http://www.vishaworld.com/
They have a shopfront at:
Visha Electronics Corporation
1st Floor, Kalpana Bldg., 
349 Lamington Road, 
Opp. Police Station, 
Mumbai 400 007

Phone: +91 22 23862650, +91 22 23862622 
Fax: +91 22 23884401

This is what these UNIBlocks looked like:

We had boards for microcontrollers, sensors, actuators, cables, mounting grids, power supplies etc. and even modules for Bluetooth, GPRS, GPS, Magnetic Cards, RFID etc.

Photos of the complete set can be found here

What could you do with these?

You could make projects complete projects like Calculators, Clocks, MP3 Players, interface with evaluation kits or create part of the circuit on breadboards.
Students could use them for laboratory type projects and EEs could use them for development/.prototyping.

Photos of more of these projects could be found here

What was the Ecosystem like?

YouTube Video

YouTube Video

More videos here