The best review of experience sampling tools I've found is here.
Specifically, to answer you question, check out "MyExperience". To quote the website:
MyExperience is a BSD-licensed open source mobile data collection tool
developed for Windows Mobile devices (including PDAs and mobile
phones) using .NET CF 2 and Microsoft SQL Compact Edition.
MyExperience is available for free on SourceForge in beta release.
Please see our wiki for documentation and our blog for updates.
MyExperience combines sensing and self-report to collect both
quantitative and qualitative data on human behaviors, attitudes and
activities in the field. Using a mobile phone's wireless connectivity
to the internet, researchers have the ability to access MyExperience
data as it's collected allowing for ongoing analysis of study data and
early detection of subject compliance or technology issues.
MyExperience is based on a three tier architecture of sensors,
triggers and actions; triggers use sensor event data to conditionally
launch actions. One novel aspect of MyExperience is that its behavior
and user interface are specified via XML and a lightweight scripting
language similar to the HTML/JavaScript paradigm on the web.