I wanted to check the date of a photo I’d taken a while back, but as it turns out, there is no way to check this information built in to your iPhone. There are a number of paid apps out there that will do this if you already have one, like iPhoto. If you don’t want to spend $4.99 on an app like that though, the app I found to take care of what I need is Camera Awesome. Search for it in the app store and download it.
Open it up and click the +
Click the italicized i in the upper right hand corner of the photo you have selected, and it will show you the information you want to see.