Pop up

The toast is in the toaster - when it pops up it will be ready.

I can't remember where I left my keys, but they normally pop up somewhere.

Across Japan, technology companies and private investors are racing to install devices that until recently they had little interest in: solar panels. Massive solar parks are popping up as part of a rapid build-up that one developer likened to an "explosion."

[…]where you should put the disclaimer for software (somewhere that the user sees it when they start the program, tho' I wouldn't do that, just put it in the 'about' box like the mpgn.com guy suggests -- otherwise, having something pop up makes it annoyware, IMHO).

My computer just popped up a warning about Internet security.