I sync my Google calendar to my devices, so if it goes belly up, I can open a new account somewhere else and start using that with little issue. I do think it'

I sync my Google calendar to my devices, so if it goes belly up, I can open a new account somewhere else and start using that with little issue. I do think it's a bad idea to rely 100% on something business critical hosted by someone else, without having your own backup somewhere. Hosted services go down eventually. That doesn't mean we can't use them, just be aware of their limitations.