[Velocity][1] - Though it is heavy on the web side of things I find it to have great speakers covering good material for anyone interested in performance, scaling, metrics, monitoring, and operations in general.

Some of the Velocity 2011 Topics and Themes include:

 - NoSQL
 - Mobile performance
 - Effective cloud computing
 - JavaScript speedups
 - TCP, HTTP, and SSL optimizations
 - Metrics and monitoring
 - Impact on the bottom line

O'Reilly Velocity happens June 14-16, 2011

  [1]: http://velocityconf.com/velocity2011