Last year, I gave a good friend a gift certificate for any small knitted item of her choosing. After some contemplation, she decided on a tiara hat. I did a search on Ravelry, and found a lot of knitted tiaras, but not specifically a hat. I eventually found two that met the criteria:
She settled on Frigging Princess, and the colors, which were black & white. Since she's a person of some sparkle, I found a new yarn from Cascade called, Hollywood, which has flashes of angelina or some such in the yarn. It's very sparkly. She mentioned wanting to add beads to it afterwards, so I hope that the sparkly yarn meets with her approval.
The hat, itself, was pretty easy to knit, although I did have to learn a bit of intarsia in the round. It was a bit fiddly at first, but I got the hang of it relatively quickly.