Like quite a few people I’ve run and biked with my phone. I ride more than I run but with running I typically track with my phone. I’ve used Nike+, Runkeeper, and currently use Strava to consolidate my training.
My preference for tracking is via a Garmin computer as it tends to capture a much richer picture of what’s happened including heart rate and in biking cadence and for some power. These additional details are tricky to acquire on a phone as very few phones use ANT+ the typical wireless tech on these devices. It’s only a matter of tine however and phones are likely to be the main route for most people – assuming of course the connectivity and importantly battery issues are resolved.
Wahoo Fitness has been pushing an accessory dongle for ANT+ connectivity and is about to release a heart rate monitor as noted by Engadget. While you do need to pay extra to gain access to extra data it’s definitely less expensive than a standalone system. Until battery life is resolved its going to be hard to justify using my phone for biking but for running this seems like a great solution.