seems fine. For bonus points we might want to support:
http://msdn.microsoft.com/en-us/library/system.security.cryptography.rngcryptoserviceprovider(v=VS.71).aspx (for IE) and window.crypto.random(10) (for firefox) which rely on the operating system to provide a secure PRNG Not sure if there's a crypto extension for webkit... http://codereview.appspot.com/1720044/show
