Team 2877, the Ligerbots, We use a manifold for most of our solenoids. It saves a ton of space and makes everything easier. Also, if you are worried about space, we have found that wiring cylinders that act together up to one solenoid helps a lot. Our gearbox shifters, opening and closing our intake, and our double CDF/Portcullis wedges all used one solenoid each even though each of them used two cylinders.
http://www.vexrobotics.com/solenoids-and-manifolds.html. This is the link to the solenoid and manifold that we use. In addition, this year we used a high flow cylinder for our pneumatic catapult shooter from McMaster Carr.