Looking at Filipo's US#26 with the double cancel made me think it would be a great theme for an ongoing thread. Not wanting to hijack his discussion, I'll start a new one here.
Show us your covers or stamps with double cancels, be they from redirecting or what have you. As long as more than one cancel, from different locations, appears on the stamp.
I'll start with a not too ancient cover, postmarked in New York NY on May 11, 1950, then again in Toronto the next day, May 12.
What you got???