I think its fine for you also, and concur with Bradford.
Been looking into it myself recently, and basically, you as an artist or photographer can do anything with it as long as its non-commercial.
Non-commercial includes art work on canvas, prints, and even selling the digital copy.
But, you cant put it onto an 'item', such as a cup or a mug (probably why Zazzle etc dont allow it), if you dont have the correct 'release' forms. Because that is then using it to sell an item, and that is 'commercial'.
If your selling the digital image, then its up to the person using the image to decide if its legal to use it in the way they are going to, not the photographers.
Some stock sites and such require you to always have a release form for buildings,cars,people etc, but that is so that they can pass on the form to the buyer, so they know 100% they can use it however they want (ie commercially), and therefor sell it at a higher price to them.
However, for non-commercial use I think its fine.
This is also my 'opinion' and not legal advice...
Rob.