Best host is Heroku, they offer you a free account that is great for development but can get expensive if you grow very big.

They certainly are easiest to start with and offer the lowest amount of trouble when scaling, all it usually involves is making bigger payments and your application scales.

I could get set up with them using this(just remember that app is still in development and wont be ready until thefall, or so the readme says).

PM me if you'd like to work out more details,for your own interest take a look at heroku.com

I really can't recommend them enough.