Ninja TC Mountain from Topeak: $55
The Ninja TC Mountain is essentially a simpler version of the MB Tailor cage above. It holds a water bottle and a multitool, but not a pump. Beneath the cage there is a small compartment that houses a 23 function multitool. Of course, the multitool has all the standard bits you would expect, but it also adds a chain breaker and spoke wrenches.
