There are plenty of ways to put a functional computer on your bike, from a phone with a bike app to one of Garmin's dedicated gadgets. Given that they're mounted as add-ons, though, they are very high-risk for theft. Helios Bars offer a more secure alternative, integrating the bike computer right onto the handlebars.
Granted, the setup doesn't provide you with a display panel for watching stats in real time. It does, however, include a facility for feedback, namely rear-facing LEDs that change color depending on how fast you ride, providing a visual speedometer throughout the trip. Since the onboard system pairs with a smartphone, you can always mount your mobile device with a Handleband (or a similar tool) if you need to monitor exact numbers in real time.
Helios Bars come in two models for now: one in a bullhorn style and another in a drop configuration. Both come with integrated headlight using CREE LEDs that provide a wide spread of illumination similar to car headlights, as well as blinkers in the rear that serve as both a visual speedometer and turn light signals (there are onboard switches you can press to set one blinker on for 5 seconds to signal a turn). Inside, the handlebars house an onboard GPS system, Bluetooth 4.0 and a variety of sensors. Paired with a smartphone, you can use it to display GPS information (track the bike's location when it gets stolen or when a friend borrows it), view a variety of riding stats, and control the lights (you can set the rear lights to display in a variety of colors or the headlights in different intensity settings). Other features include aluminum construction and onboard batteries that can last for six hours when the headlight is set at the brightest.
Originally a Kickstarter project, Helios Bars is now in full production. You can order a unit for $199.