I've always wanted to live up in the mountains somewhere, but unfortunately have never got the opportunity to do so.
Perhaps the closest I'll get to experiencing mountain life is by installing this Mountains theme on my Series 60 phone.
The theme not only changes the background wallpaper image to one of a mountain range at dusk, but it also alters the layout of your menu items in order to give them a more rugged touch.
In terms of realism, this theme is a little cartoony. The background is a vector drawing rather than a photograph of a mountain range and the menu icons have an orange Inca feel to them.
That's not to say this is a poor theme though, and if you're looking for a way to liven up your mobile and are a fan of mountains then I'm sure you'll love this one.