You can't load balance two or more SQL Servers without huge amounts of work to keep the two databases in sync eg though (peer-to-peer replication). A HTTP load balancer requires two or more web servers, if there's only one web server, there's nothing to balance the load across.
Typically you'd load balance a group of web servers and they'd all talk to a single SQL Server, probably a more powerful server.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability