The guy in 1 created X which is considered the ultimate geek toy. 2,3,4 are his less famous creations among many others.

1. 

2. 3. 4.

Identify 1 and X

Cracked by: madhur , jayanth , nishansolo , Atul Mathew , Dibyo , Arun Krishnamoorthy , shenoyvarun86 , udupendra , Arjun Chennu , duriel , Dhananjay , RajT , Tathagata Chatterjee , shashank , vaibhav008 , varuns88( Welcome to BB! ) and Shreyas.

madhur, jayanth, nishansolo, Atul Mathew, Dibyo, Arun Krishnamoorthy, shenoyvarun86, udupendra, Arjun Chennu, duriel, Dhananjay, RajT, Tathagata Chatterjee, shashank, vaibhav008, varuns88 and Shreyas