Fetching the balance of a number of addresses would be quicker using the /multiaddr API call rather than calling addressbalance individually e.g.

https://blockchain.info/multiaddr?active=19BgLUEFhKAxbcELVMafbvZb4RCzGAkraa|1A8JiWcwvpY7tAopUkSnGuEYHmzGYfZPiq

If you don't want transactions included add a simple=true parameter as follows:

https://blockchain.info/multiaddr?active=19BgLUEFhKAxbcELVMafbvZb4RCzGAkraa|1A8JiWcwvpY7tAopUkSnGuEYHmzGYfZPiq&simple=true

Looks like a good concept.