The dashboard indicates missed calls rather clearly. So, tap one button (or hit one keyboard shortcut) and you can see missed calls. Either that, or, this being Maemo, wait for somebody to implement a widget to do this (reasonably trivial). I'm bothering fiferboy to do it as we speak. This is the thing about Maemo, if it's not there out of the box, it's almost always a trivial task for somebody to implement it, so canceling over something as minor as this would be . . . silly.