Can Messages display the timestamp of every incoming message?

I was chatting with someone via Messages.app on my iPhone, and they sent me a message saying "call me in 20 minutes". I was away from my phone when they sent it, so I didn't know when they sent the message, and therefore didn't know when to call.

I know that Messages.app displays a start time for new conversations, but I just want to get the time of a specific message.

Tap-and-hold and double-tap on the message just give a "Copy" context item.

How can I see the time of an incoming message?

iOS 7, which is now in the wild, can indeed show timestamps for every message. Just slide your finger right to left in a conversation.

Image: The Verge

(I literally yelled "finally!" while sitting at my desk when I read about this.)

I managed to view the timestamp of the most recent message by going back to the main Messages menu.
That displayed the most recent activity timestamp next to each conversation, and since I hadn't sent a response, the most recent message was the "call in 20 minutes" message.

I still can't find a way to get at the timestamp of an arbitrary incoming message, but this addressed my immediate problem.