I better write this down before I forget it again: ctrl+shift+6 x
If this makes absolutely no sense to you I will explain:
When you run commands like traceroute, ping and others within Cisco IOS you can abort them. But you can’t use the usual ctrl+c (that would be to logical I guess), you need to press ctrl+shift+6 and THEN press x.
There’s probably a good explanation for this, but I still feel that it is horribly cumbersome. Especially since I don’t use it that often, so I forget it from time to time :P