Photo sponsored by: link?

[Braintangle]

Hello.

I am looking closely at Photopost. I'm curious to know if it is possible to include a "Photo sponsored by:" link with every image? Or even better, a way to include a custom banner under each photo?

For example...
[1] I upload a photo of a canon digital camera.
[2] And insert code like this: <a href="www.amazon.com/canon_camera.php">Buy this camera here</a>
[3] Or a banner code like this: <a href="www.amazon.com/canon_camera.php"><img src="http://www.mysite.com/banner.gif"></a>
[4] The text link or banner is displayed immediately under the photo.

Is this functionality already built in? Or could it be done with BBCode somehow? Thanks!