If you like your vacuum-cleaning robots on the fancy side, iRobot's latest addition to the Roomba lineup has a few features that make it easier to use.
The main selling point for the 790 is a radio-frequency remote control that lets you steer Roomba around from almost anywhere in your house (also perfect for when your cat pounces on it), clean specific spots, schedule vacuuming, and order the bot back to its charging station.
For $699.99, you also get additional accessories that the Roomba 780 doesn't come with, namely a snazzy carrying case, an extra virtual wall to confine Roomba to certain areas, two extra sets of filters, extra brushes, and a screwdriver.
Other than the above, the 790 is much the same as the 780, and likely cleans just as well. It has room to room navigation and a power-management system that extends the battery life compared to earlier cleaners.