We envision ubiquitous autonomous mobile robots that coexist and interact with humans while performing assistance tasks. Such robots are still far from common, as our environments offer great challenges to robust autonomous robot perception, cognition, and action. In this talk, I present symbiotic robot autonomy in which robots are aware of their limitations and proactively ask for help from humans, access the web for missing knowledge, and coordinate with other robots. Such symbiotic autonomy has enabled our CoBot robots to move in our multi-floor buildings performing a variety of service tasks, including escorting visitors, and transporting packages between locations. I will describe CoBot's fully autonomous effective mobile robot indoor localization and navigation algorithms, its human-centered task planning, and its symbiotic interaction with the humans and with the web. I will further discuss our ongoing research on knowledge learning from our speech-based robot interaction with humans. The talk will be illustrated with results and examples from many hours-long runs of the robots in our buildings.