An account-based webwallet is quite similar to a Paypal after all.
And that's what (Y! Combinator's) CoinBase is aiming to do .. make using bitcoin appear little different from the experience when using PayPal.
As far as ease of use, the mobile clients are pretty user friendly. I don't know how something like BitcoinSpinner for Android could be any simpler, for instance.
(well, some way to automatically backup the wallet's "master private key" without having to go through the "take a picture of the QR code" would be one method, but that's just a little unusual and inconvenient, not something necessarily difficult.)