Load balancing has been an increasingly important issue for handling computational intensive tasks in a distributed system such as in Grid and cluster computing. In such systems, multiple server instances are installed for handling requests from client applications, and each request (or task) typically needs to stay in a queue before an available server is assigned to process it. In this paper, we propose a high-performance queueing method for implementing a shared queue for collaborative clusters of servers. Each cluster of servers maintains a local queue and queues of different clusters are networked to form a unified (or shared) queue that may dispatch tasks to all available servers. We propose a new randomized algorithm for forwarding requests in an overcrowded local queue to a networked queue based on load information of the local and neighboring clusters. The algorithm achieves both load balancing and locality awareness.