A good companion for this would be a browser extension that interfaces with the bitcoin network so interactions could be streamlined. The extension does not need to be a bitcoin miner, simply an interface for your existing account(s).
The usage pattern would follow:
1) Install the extension
2) Configure extension with your bitcoin address(es).
When encountering a site using bitwillet:
1) User clicks "Pay"
2) bitwillet overlay appears with generated bitcoin address to send payment to. bitcoin address is clickable.
3a) Clicking the bitwillet address interfaces with the bitcoin extension to send the payment from your account to the one provided by bitwillet. A "Are you sure?" confirmation should appear before the transaction is complete.
3b) Alternatively, the overlay interfaces directly with the extension and bypasses the need for the user to click the bitwillet address. Confirmation screen should still be used.
4) bitwillet overlay updates its text to tell the user the transaction is in process.
5) When the transaction is complete, the overlay message changes again to inform the user.
