Flip may have pioneered the idea of pocket Internet video cameras, but it has been a little bit slow moving up to HD. The diminutive Mino was the first to be updated (to the MinoHD naturally}, and Creative had already beaten it to the punch with the Vado HD. Now, at last, the original Ultra has taken a step higher on the resolution ladder.
The UltraHD doesn't look significantly different to the standard-definition Ultra. It's a few millimetres fatter, but you would be hard pressed to notice even when the two are placed side-by-side, and it will fit just as easily in your pocket. However, where the Ultra is available in four different liveries, including pink and yellow, the UltraHD takes a more monochromatic approach and can only be purchased in white or black.
Inside, the UltraHD bears a lot of similarity to the MinoHD. It uses the same 1/4.5in CMOS sensor, and records video exclusively at 1,280 x 720 with 30 progressive frames per second, using a 9Mbits/sec data rate. But the video compression system is Flip's Video Engine 3.5 rather than 3.0, and the UltraHD also sports 8GB memory, twice that of the MinoHD. This means it can store two hours of footage, but as with all previous Flips there is no option to upgrade capacity via removable storage.
One thing you can swap out is the battery. The original Flip Ultra relied on AA cells, so you could simply pop in new ones if you ran out of power when out and about. The Mino, on the other hand, traded this flexibility for the space saving afforded by a built-in rechargeable battery. The UltraHD takes a third route, still using AA cells but with a rechargeable pack included in the box. This is topped up every time you plug the unit in via its USB connection, and lasts over two hours. But if you run out of juice on the road, you can still just pop in some alkaline cells instead.