In our company we have established some rule that from time to time (once a week or every few days) the whole team spends half an hour of testing their own software in its current state. We established this because we are producing a multi-user web application and it turned out to be a good way to find multithreading-related errors when the whole team of e.g. 10 persons are clicking around in parallel on the same server.
However it turned out to be much more valuable than initially thought, especially because developers get early feedback on how their components really feel when used, also from other devs. Additionally we usually find a huge amount of bugs because in this half hour of intuitive testing often functionality is executed which was not even part of recent changes.
So basically the question is if there is a name for this kind of the-whole-team-and-also-the-devs-click-around-for-some-while tests?