As the Apple Watch goes on sale Friday, it's unclear if the gadget and others like it can attain the utility and prominence smartphones have in the past eight years. Ryan Emberley/AP hide caption

itoggle caption Ryan Emberley/AP

Outfitted with two color cameras that run on batteries, the PillCam Colon capsule is being billed as a less invasive and less expensive option to a colonoscopy. Given Imaging hide caption

itoggle caption Given Imaging

Google co-founder Sergey Brin wears Google Glass glasses at an event on the University of California, San Francisco's Mission Bay campus on Feb. 20. Jeff Chiu/AP hide caption

itoggle caption Jeff Chiu/AP

The iGrill on display at Macworld 2011in San Francisco. Tony Avelar/Bloomberg via Getty Images hide caption

itoggle caption Tony Avelar/Bloomberg via Getty Images