FTA:
"In their time study with the Yupno, now in press at the journal Cognition, Nunez and colleagues find that the Yupno don't use their bodies as reference points for time – but rather their valley's slope and terrain. Analysis of their gestures suggests they co-locate the present with themselves, as do all previously studied groups. (Picture for a moment how you probably point down at the ground when you talk about "now.") But, regardless of which way they are facing at the moment, the Yupno point uphill when talking about the future and downhill when talking about the past."
"In earlier research, Nunez found that the Aymara of the Andes seem to do the reverse, placing the past in front and the future behind."
The second example seemed odd to me, but makes a lot of sense with your analogy.