I'll start by saying I'm by no means a gardener and I usually kill anything that's green and lives in a pot, however I'd like to say this one is doing well, judging by its height. It no doubt needs to be repotted very soon, I can see blotches appearing on the leaves.
My girlfriend and I are debating the identity of this plant. We bought it a while back and subsequently lost the label with the name on it.
We seem to have some lingering memory that it might be some kind of Poppy, but we are unsure - and Googling Poppies turns up plants that look nothing like this one here.
It also seems to be bearing fruit that look a little like small peppers or chillies to me, but again, I'm not a botanist.
So, what kind of plant is this?
Here are some pictures (click on each for a larger image)
The flowers eventually came through, and they look exactly like the plant Shanna mentioned in her answer. I always thought poppies were red :)