The iDevices are great as you just keep your finger on the letter a little longer and all the alternatives pop up. But those goshdarn old-fangled computer keyboards...well...
I'm saving this for my own reference! I've been typing a lot of recipes and I'm tired of googling it every time. And you might find it useful, too.
ALT-248 or ALT-0176
Bake at 350°
I wowed someone at work with this one:
ALT-137 or ALT-0235
Because you can't spell Charlotte Brontë without it.
Here's the link for international letters.
And a massive list of all the codes.