Load Balanced Servers - Do they actually work?

Does anyone know anything about load balanced servers. I am currently looking for another host but I can only find load balanced servers at PowWeb. I am hesitant to give them my credit card number because the last time I had $6000 worth of fraud when their servers were compromised.

Does load balancing actually work?

I would prefer Dreamhost but Load Balancing sounds so cool. You server goes down and your site stays up by being hosted on other under utilized servers.