Often you just want to notify the user that something has occurred, but there's really no need for any input from them. In this common scenario, I sometimes see code like this:

MessageBox.Show("Something has occurred", "Something", MessageBoxButtons.OK);

This code, as we all know, causes a little pop-up window to appear with only an OK button. Now here's the thing: this code blocks (the UI thread). But in the vast majority of cases, it seems to me, if you only have an OK button, there's very little need to block. (Isn't the purpose of blocking typically to receive some input from the user? And if the user's only choice is "OK," in this typical case, isn't blocking pretty pointless?)

Obviously I could just write my own little form that does basically exactly what MessageBox.Show does, except that it returns nothing (no DialogResult) and doesn't block. But I was just wondering if something like this exists already that I didn't know about.