There are a number of recurring TYPO3 events and conferences. Each year, the TYPO3 Community organizes a snowboard tour "T3Board" in the mountains of central Europe, giving TYPO3 developers an opportunity to meet face-to-face. Furthermore, there is an annual "Developer Days" event that aims to give PHP developers a chance to collaborate and focus on the TYPO3 core.
There are annual conferences held in the US and in Europe with talks aimed at web marketers, site integrators and developers. Many regions also host active TYPO3 usergroups, which are invaluable sources of shared knowledge.