1. Creating a "physical" bit coin representation that can help overcome the psychological barriers non-tech people have to a currency that only exists virtually.
2. Helping people who like Bitcoin, but somehow don't trust their own impulse control not to sell, and having it physically and with the wallet address hidden even from themselves is one way of beating their own impulses.
I am in neither of those two groups of people.
I guess an argument could be made that they're more secure in the physical world than sitting on your computer, but if your computer isn't secure I think you have bigger problems.
I've seen a few threads talking about designs for paper wallets before, but having trouble finding them atm. Just search "paper wallets".
ED: Here you go, check this out. https://bitcointalksearch.org/topic/the-official-bitcoinpaperwalletcom-thread-updates-and-news-169836
You are thinking really short term about that. Some people just want to buy it, print it out, and forget about it. There's no really better way of doing it.