Originally Posted by adamrice

Although a bike computer might be the right answer for you, I use an iOS app called Cyclemeter (there's also an Android version) that can sync to Strava, and can interface with a bunch of sensors over Bluetooth (I've seen an ANT+/Bluetooth bridge, but have never used it).

I don't think it'll do live segments, but I'm not on Strava so I can't really say.