Background: The SenseCam, a small camera that is worn on the chest via a lanyard, is increasingly being deployed in a health research. However, the SenseCam is not yet in widespread use due to a variety of factors. It is proposed that the ubiquitous smartphone can provide a more accessible alternative to the SenseCam. Purpose: To perform an initial evaluation of the potential of the smartphone to become an alternative to the SenseCam. Methods: Adults were supplied with a smartphone running lifelogging software which they wore on a lanyard. Participants wore the smartphone for up to a day and the resulting lifelog data was both manually annotated and automatically analyzed for the presence of visual concepts. The results were compared to prior work using the SenseCam. Results: In total 166,000 smartphone photos were gathered from 47 individuals, along with associated sensor readings. The average time spent wearing the device across all users was 5 hours and 39 minutes (± 4 hours 11 minutes SD). A subset of 36,698 photos was selected for manual annotation by 5 researchers. Software analysis of these photos supports the automatic identification of activities to a similar level of accuracy as for SenseCam images in a previous study. Conclusions: Many aspects of the functionality of a SenseCam can largely be replicated, and in some cases enhanced, by the ubiquitous smartphone platform. This makes the smartphone a good candidate for a new generation of wearable sensing devices in health research, due to its widespread use across many populations. It is envisioned that the smartphone will provide a compelling alternative to the dedicated SenseCam hardware for a number of users and application areas. This will be achieved by integrating new types of sensor data, leveraging the smartphone’s real-time connectivity and rich user interface, and providing support for a range of relatively sophisticated applications.