In this article, we examine the ethical dimensions of researching the mobile, ubiquitous and immersive technology enhanced learning (MUITEL), with a particular focus on learning in informal settings. We begin with an analysis of the interactions between mobile, ubiquitous and immersive technologies and the wider context of the digital economy. In this analysis, we identify social, economic and educational developments that blur boundaries: between the individual and the consumer, between the formal and the informal, between education and other forms of learning. This leads to a complex array of possibilities for learning designs, and an equally complex array of ethical dimensions and challenges. We then examine the recent literature on the ethical dimensions of TEL research, and identify key trends, ethical dilemmas and issues for researchers investigating MUITEL in informal educational settings. We then present a summary of research dialogue between the authors (as TEL researchers) to illuminate these MUITEL research challenges, indicating new trends in ethical procedure that may offer inspiration for other researchers. We conclude with an outline, derived from the foregoing analysis, of ways in which ethical guidelines and processes can be developed by researchers--through interacting with participants and other professionals. We conclude that ethical issues need to remain as open questions and be revisited as part of research practices. Because technologies and relationships develop, reassessments will always be required in the light of new understandings. We hope this analysis will motivate and support continued reflection and discussion about how to conduct ethically committed MUITEL research. (Contains 2 notes.)