Problem with Canon DSLR Pop Up Flash?

Got a Canon DSLR camera and its built-in flash doesn’t want to pop up? Seemingly this has been a mechanical design issue for some time afflicting many models. The likely fix? Unjam the sensor in the flash hot shoe so it doesn’t think there’s an external flash mounted.

Here’s an old discussion on Flickr about this topic including a pic of the external flash detection switch/sensor.

Update: I tried propping up the metal tab covering the switch and sure enough with a bit more room, the external flash detection switch raised and now my built-in flash works once again.