First I would like to clear a few things up if I may….
SQL Server Clustering is an availability technology that is built on top of Windows Clustering. It provides redundancy at the hardware level and has no relation to the technique known as load balancing, i.e. distribution of a processing load.
Further to this, Database Mirroring and Log Shipping are also technologies for primarily implementing availability of varying forms.
Now onto the original question…..
Unfortunately there is no ready to go “out of the box” solution for load balancing in SQL Server.
You can use SQL Server Replication Technologies to implement a distributed database environment that also factors in distribution of transaction processing load however, your application needs to be “aware” of the underlying architecture.
This approach requires development and customisation of a given application in order to deliver a service that is load balanced.
I hope what I have detailed is clear and makes sense but of course please feel free to fire your queries over to me directly.