Plaintext question. Googling will be severely frowned upon.

What are these some examples of:

Server: '; DROP TABLE servertypes; --
X-nananana: Batcache
X-Fry: Please, Mr. Nixon! We're appealing to your sense of decency!

Cracked by: badideabear , Ananth , Bharath , Manish Achuth , rickde , Sujoy , Rogi , KK , Sumanth Patlolla and raklodramA

Answer:
Easter eggs hidden in HTTP headers returned by many popular sites (reddit, wordpress, and an older slashdot). Check boiledbeans.net for some fun :P