The station didn't sell them in four possible outlets. The Doctor Who Experience (which was awesome) didn't sell pencil sharpeners but it did sell pencils and rubbers. We wandered around Cardiff Bay and went to Techniquest, which was awesome, and we got a pencil sharpener in their gift shop.
I pointed out some cormorants in the Bay. Bear asked why I thought they were cormorants and not crows. I pointed out the long necks. Bear suggested that they could be mutant crows that just looked like cormorants. I suggested that if they look like cormorants and are on a landing point in the bay then there was a good chance they were cormorants. Bear suggested they were robots and how could I tell at this distance. I pointed out that no-one was charging people to look at them.
To be honest, I'm not that confident in my skill in identifying seabirds. I've had a quick check of the internet and I probably got it right. It definitely wasn't a crow.