I'm trying to find a few options of ways to do high availability DNS hosting for a few existing websites. This morning, the company I work for was brought to its knees because the DNS hosting we have for our domains through our registrar ([bulkregister.com](http://bulkregister.com)) went down. I'm now being tasked with finding an alternative which will not put us at the mercy of a single DNS provider.

What we're looking for:

* No single point of failure.
* Time effective.
	+ One solution that has been suggested is to do multiple DNS hosts. This seems like a great alternative, but we have over 20 domains, and updating an IP address on all of those domains across two providers is prohibitive.
* Cost effective.
	+ I have to sell this to upper management. Joy is me.

So what methods exist which support this? I'm more of a programmer myself, but they've tasked me with this, so I wanted to get the opinion of people more experienced than I am.