Motivated by the continued search for methods to reduce participant burden and non-response, and improve the quality of travel data, this paper details the development of a new online travel/activity diary to support a major longitudinal investigation of travel in Sydney, Australia. The diary employs several innovative features designed to simplify the process of data entry, and improve participant recall and completeness of travel, including auto-fills, prompts, trip editing capabilities, favourite trips and a dragand- drop technique for capturing travel mode. An additional innovation is the ability to view a GPS-based Google map of daily travel while completing the diary to assist with recall. The diary is tested on 37 participants, with a range of diagnostics provided to assess their comprehension and interaction with the diary, reaction and burden, and completeness of data provided. Overall, 89% of participants complete all seven days of the diary with 75% indicating no issues once they become accustomed to how it works. Trip entry times average around two minutes/trip with three-quarters of trips entered within 24 hours of being made and 96% of trips provided with complete details. In terms of the GPS component, while the data itself is of variable quality and the optional viewing of trips is lower than anticipated, those carrying a GPS report more trips/day and segments/day, fewer missing days, and provide more complete trip data.