Homemade Antigravity?

Well, this is probably true for translations from that languages to english, but I'm pretty sure for one of these: shlimazl would be exactly "salado" in the spanish spoken in Costa Rica, despite being a informal adjetive, it does fit perfectly to the meaning.

BTW: "Salado" means salty literally.

I am not sure that 'Salado' has the 1,000 years of jokes told about shlimazls. Chronically unlucky is only the start. Think of Polish jokes combined with Blond jokes with an overtone of "At he is one of us."

Just to let you know that "a chronically unlucky person" in German is a "Pechvogel". Literally an unluckybird.

However there is no word for "not thirsty" in German. Try that.

shlimazl have a translation in spanish: Gafe

That's easy to translate. Try "Democrat."

The Finnish word Sisu, meaning roughly 'courage beyond common sense' should be up there.

My favorite is the Swedish word gökotta: "to go out early in the morning, traditionally on Ascension day, to listen to the birds of spring, especially the cuckoo."

Regarding this topic, see http://en.wikipedia.org/wiki/Ilunga which says "When asked for confirmation by one reporter, representatives of the Congo government recognized the word only as a personal name." and see the commentary at Language Log at http://itre.cis.upenn.edu/~myl/languagelog/archives/001104.html .

This could go for phrases that don't really translate well too. Brazilians have "dar um jeito" which basically means find a way, but it is much deeper than that, delving into the entire cultural identity. Words and phrases like that simply do not translate well.

Many Dutch people speak or understand a few languages, like English and German and a bit of French.
But there is one, very common Dutch word that is notoriously hard to translate or even explain: 'gezellig'.
'Gezellig' is a feeling, an atmosphere. It is usually translated as 'cozy', but it's more than cozy. A situation or room can be 'gezellig', but also people and objects. It's warm, peaceful, you forget time, there is togetherness, no complications or problems.
Some could even say Neatorama has a 'gezellige' quality to it.

My wife likes the Indonesia "jalan jalan" which means to stroll or walk about, usually with the purpose of "resting one's eyes".

I often use the word "shadenfreuden" - finding humor in others misfortunes.

It would be nice to see a larger list of words difficult to translate into English.

A great word that has no equivalent translation is the Swedish concept of 'lagom'.

Lagom can be applied to many things. It could almost denote sufficient, enough, moderate, ample, appropriate but it is much more than that.

A portion of food could be 'lagom stor' (big enough), not too much, not too little. One's state could be lagom without being too rich or too poor. A conversation or meeting could reach a state of lagom to represent concensus.

It is difficult for me to explain, I personally think it is rooted in socialist culture where excess has no place.

I often hear native english speakers claim that there is no word in english for whatever word they are looking for from the other language they have learned. More often than not, it is because their vocabulary is limited, not the language itself.

There's two that catch my interest. Both from ancient languages. In latin, it's the ethic dative. It is either mihi or tibi (literally "to me", "to you"). One might say, "Habet seruam, tibi". "habet seruam" means "he has a female slave". But adding the tibi, means roughly "this should be of particular interest to you". It really doesn't translate very elegantly.

The other is in ancient greek. I believe this is more common in attic and homeric greek than koine. In english, verbs have either an active(I am doing x) or a passive(x is being done to me) voice. Ancient greek adds a middle voice. If we take, for example, the verb "to loosen". In greek, with the active voice, it means you are untying something. With the passive voice, you are being let free. But, in the middle voice, it means you are being ransomed.

The middle voice simply has no direct parallel in english.