Alt-Gr is left of the right-hand windows key.

That looks like spacebar... I dunno about these british keyboards, I think they are trying to corrupt people.

Quote from dawesdust_12 :

The Apple layout does have it's benefits though, to do umlauts, it's alt+U, then whatever vowel you want umlauted, to do the accents, it's alt+` or alt+e for the various accents. It just takes some getting used to, but once you do, It becomes tons easier.

Isn't that what every layout with accents does? I hit the "´" key, for example, and then press the vowel I want accented, like: "á"