Paper Wallets

[Shagnasty]

Okay, a few questions. First of all, are paper wallets still relevant? Secondly I have a question regarding their usage. Not too skilled in the technical lingo, but basically a paper wallet is a private key for an address that has coins in it? Basically, if I wanted to sell a paper wallet to someone, what is stopping me from giving them the slip of paper, and when they leave, I just hurry up and transfer the bitcoins to a different wallet before they do?

[nobbynobbynoob]

Nothing, which is why promissory notes containing the private key are only really worthwhile where the issuer can be fully trusted.

[Revalin]

Paper wallets are usually more about secure storage than a convenient form of in-person commerce.

Paper coins can be used for face to face transactions though:  You give the merchant a slip of paper with the secret key in a QR code; they immediately import it and "sweep" the coins to their own address while you wait; they then issue your change either as a key on a paper receipt (and you sweep it when you get home) or transfer it to a pubkey you specify.  This is reasonably secure method for everyone.