Open sesame!

The tale of Ali Baba and the Forty Thieves is world famous, so it's no surprise that it's just as well known in Japan. What did surprise me, for some reason, is the translation of 'Open Sesame!'.
開けゴマ (ひらけごま)
Literally, 'Open! Sesame'. Perhaps because it's a magic word, it hadn't occurred to me that 'sesame' would be literally translated.

However, ごま lends itself to some other Japanese phrases that don't translate quite as literally.

へそのゴマ
Literally 'navel sesame', an interesting way of describing belly-button fluff. Perhaps I'm weird, but it doesn't remind me much of sesame.

ごま塩ノイズ 
Sesame and salt noise: black and white noise. A common condiment is ground black sesame with salt, and it does look quite like static noise on a television, albeit more static than static noise, which, ironically, isn't actually static. The katakana word ノイズ means specifically 'random noise' rather than loud sounds in general.

ごますり or ごまをする
Grinding sesame: idle flattery. The verb here is する 'to grind; to rub'. Not to be confused with する 'to do', it conjugates normally, so the polite form is すります, not します. The grinding is specifically with a mortar and pestle, and the ground sesame sticks to everything it comes into contact with. Therefore, and this is a stretch, it means trying to 'stick' to everybody, hence flatter. This has led to a gesture for flattery: rubbing one hand against the other as though grinding sesame.

ごまふ　(胡麻斑)
'sesame freckled' is used in the names of flora and fauna to mean black spotted or speckled. The spotted seal is 胡麻斑海豹 ごまふあざらし, the kanji meaning a sesame spotted sea leopard.

ごまかす 
To deceive. Actually, this may or may not be sesame related. When written in kanji, these days it's usually written as 誤魔化す misunderstand + magic + -ise (verb forming ending, as in socialise), but this is 'ateji', with kanji used only for their sounds. One theory is that it comes from 護摩 ごま, a Buddhist cedar stick burning ceremony, with a verb ending かす. The ashes from this would be sold, but often you'd be more likely to be getting burnt garden waste from the not-so-devout ash salesman. So 'are you cedar-sticking me?' came to mean 'deceive'. The other explanation does involve sesame. 護摩菓子 (ごまかし), is sesame flavoured sweets, in this case referring particularly to an Edo period (1603-1868) cake called 胡麻胴乱 (ごまどうらん). This was hollow inside, so looked considerably much more substantial than reality. Therefore, 'sesame-caking' was outright deception.

The more interesting etymologies have come from http://gogen-allguide.com/.