If the signer is sitting next to you, there is no need to wait for an email. Right after you send, the confirmation screen offers to open the signing screen on this device. You can also do it later: in My Documents, choose Resend on the document (or in its ⋮ menu), then Sign in person next to the signer. Hand them the device, and they sign on the spot. If you are one of the signers yourself, choose Sign now.