All this data is potentially out of date, and should be taken with a truckload of salt
What is the use of shuttles?Shuttles are designed to provide a cheap and fast way to travel between systems. They are cheap to construct and buy off the market, owing to the lack of fitting slots for modules and their limited cargo space, but they move rather fast for their price, thus making them an excellent choice for travel. While shuttles have been known to be used in the role of scout or survey ships, their most common use is as intermediary travel in order to pick up other, more expensive ships. It cannot be stressed enough that these ships can be one- volleyed by basically anything more than a noob ship, so stay out of battles and don't bug people who might be tempted to gank you.
Removal of NPC Sell Orders
Before April 2008, shuttles were sold by many NPC corporations for 9000 isk apiece in nearly every empire system. This capped the price of tritanium at 2.4 ISK per unit, since a shuttle can be reprocessed into 2,500 tritanium. To remove this cap and further open up Eve's economy, CCP's economist Dr. EyjoG suggested making shuttles an (exclusively-) player-manufactured item. This was implemented in a surprise patch, suddenly removing all shuttle NPC sell orders.
At least five somewhat-unique shuttles exist in the game.
- Apotheosis — Given out for Eve's fifth birthday.
- Goru's Shuttle — Goru Nikainen's shuttle, from a COSMOS mission. 
- Interbus Shuttle — Distributed as a one-off reward for those who purchase the boxed game since its re-release via Atari in 2009.
- Guristas Shuttle — Mission completion reward from COSMOS agent Akemon Tolan.
- Zephyr — Unique Solar wind driven ship, able to deploy probes, and ignored by the Sleepers.