Lately my 3 year old's favourite passtime is to come sit on my lap while I'm trying to work (or surfing HN or whatever) and ask, "Can I press this key?" (Shift? "Uh, ya, sure.") "Can I press this key?" (Ctrl? "Sure.") Some of them make you think though. (F2? What will that do in this context?)
It's not among my most productive times, but it's fun. :)
I let my 3 year old play with my laptop at times, by giving her a full screen xterm running bash in a separate tab on my tiling window manager. She mostly likes to type the letters she knows (her initial, my initial, uncle's initial etc) but it's surprising how often she manages to Ctrl-R or Windows-Shift-3 or some other combo that makes things go haywire.
Haha! Fortunately, her initials are not all in ASCII, so it's not gone wrong yet. But true, I should set her up with a user account that doesn't have write access on anything.
I told my 2 and a half year old that the "S" key is the snake key, so now he always asks "can i press snake?". He's also found a second snake (the 5 key).
It's not among my most productive times, but it's fun. :)