The undocumented history about bitcoin and it's wallets
And without this thread I certainly would never have known about these guys, wounder where they disappeared to.
And if memory serves me right isn't local bitcoins a long serving wallet provider despite being mainly labeled as a p2p exchange...or it doesn't just fit in this category.
StrongCoin is still around.
An exchange is an exchange and should be treated as such, they did/do encourage their users to treat them as a wallet at times but you're at their mercy if they decide to freeze your funds, if they get hacked, etc.