I have a friend here that keeps saying he would like some of those yellow "Wanderweg" stickers just because they're cool. I have explained that surely if they were for sale, people would buy them and put them on every non-hiking path they could find. Sure enough, a quick google search (for "wanderweg aufkleber") turns up nothing helpful. Nonetheless, I thought I'd ask if anyone out there knows if these stickers can be bought. That would make a really easy (and "cool") Christmas gift.

According to this website not stickers, but the pictured metal signs with the wanderer pictogram are on sale for about 20 Fr.

You can even have your personalised direction sign with four destinations and time specifications for about 190 Fr. (p.e. ETH - 20min, Madrid - 19d 10h )

You can ask them if they sell the stickers, or the "Wanderweg" signs with crest of the canton, too. Their phone number is 031 370 10 20 but since you don't know German or French well you may prefer to write them a mail in English to info@wandern.ch.