Any Aussies around?
This is what I got in an email "did you know that?". Could there be any trouth in it?
<blockquote>Quote
<hr>When the English settlers landed in Australia, they noticed a strange animal that jumped extremely high and far. They asked the aboriginal people using body language and signs trying to ask them about this animal. They responded with ’’Kan Ghu Ru’’ the english then adopted the word kangaroo. What the aboriginal people were really trying to say was <hr></blockquote>
I have heard variations on this story for places and creatures all over the world, so I find it immediately suspect.

No truth to that, even though I did hear it from my father.
The Online Etymological Dictionary says:
1770, used by Capt. Cook and botanist Joseph Banks, supposedly an aborigine word from northeast Queensland, Australia, usually said to be unknown now in any native language. However, according to Australian linguist R.M.W. Dixon ("The Languages of Australia," Cambridge, 1980), the word probably is from Guugu Yimidhirr (Endeavour River-area Aborigine language) /gaNurru/ "large black kangaroo."
"In 1898 the pioneer ethnologist W.E. Roth wrote a letter to the Australasian pointing out that gang-oo-roo did mean 'kangaroo' in Guugu Yimidhirr, but this newspaper correspondence went unnoticed by lexicographers. Finally the observations of Cook and Roth were confirmed when in 1972 the anthropologist John Haviland began intensive study of Guugu Yimidhirr and again recorded /gaNurru/." [Dixon]
The Endeavour River region was where Cook and Banks first noted the word.
"Kangaroo court", by the way, according to the Online Etym Dict "is Amer.Eng., first recorded 1853 in a Texas context (also mustang court), from notion of proceeding by leaps. "
What I thought was strange is that it can't be verified. There are no sure sources. And it's been only a couple of hunderd years back.

i don't know that it's strange: there were an estimated 200 distinct aboriginal languages in use in australia at the time of british colonisation; the figure is now around 20. it's quite possible that the language or languages from which 'kangaroo' originated no longer exists.
so, perhaps not strange that no sure sources remain, but certainly sad.
btw: the OP (in various guises) is a fairly common joke here in australia. as in, 'did you know that 'kangaroo' really means, 'what the hell language are you speaking, you crazy whitey?!' etc.

The OED discusses the word's origins at remarkable length:
Stated to have been the name in a native Australian lang.
Cook and Banks believed it to be the name given to the animal by the natives at Endeavour River, Queensland, and there is later affirmation of its use elsewhere. On the other hand, there are express statements to the contrary (see quots. below), showing that the word, if ever current in this sense, was merely local, or had become obsolete.
The common assertion that it really means 'I don't understand' (the supposed reply of the native to his questioner) seems to be of recent origin and lacks confirmation. (See Morris Austral English s.v.) 1770 Cook Jrnl. (1893) 224 (Morris) (Aug. 4) The animals which I have before mentioned, called by the Natives Kangooroo or Kanguru. 1770 J. Banks Jrnl. (1896) 301 (Aug. 26) The largest [quadruped] was called by the natives kangooroo. 1787 Anderson in Cook's Voy. (1790) IV. 1295 We found, that the animal called kangooroo, at Endeavour River, was known under the same name here [in Tasmania]. 1792 J. Hunter Port Jackson (1793) 54 The animal 'called the kangaroo (but by the natives patagorong) we found in great numbers. 1793 W. Tench Compl. Acc. Port Jackson 171 The large, or grey kanguroo, to which the natives [of Port Jackson] give the name of Pat-ag-a-ran. Note, Kanguroo was a name unknown to them for any animal, until we introduced it. 1834 Threlkeld Austral. Gram. (Hunter's River) 87 (Morris) Kóng-go-róng, the Emu_likely the origin of the barbarism, kangaroo, used by the English, as the name of an animal called Mo-a-ne. 1835 T. B. Wilson Narr. Voy. World 211 (ibid.) They [natives of the Darling Range, W.A.] distinctly pronounced 'kangaroo' without having heard any of us utter the sound. 1850 Jrnl. Ind. Archipelago IV. 188 (Kangaroo.) It is very remarkable that this word, supposed to be Australian, is not to be found as the name of this singular marsupial animal in any language of Australia 'I have this on the authority of my friend Captain King.

I don't mean in any way to run down nette, who is very knowledgeable about Australia, but I would suggest posting this question on the Australia/New Zealand branch. There are lots of people there who would jump into this one.
Yes I've heard that one before, I remember my linguistics lecturer at uni telling that story, probably not true but funny nonetheless. I heard another funny story about the meaning of the word: Australia" from an Indonesian friend of mine. As we know it comes from "Terra Australia" meaning "Great Southern Land”, but he had an interesting take. He said that captain cook had a servant from one of the outlying islands of Indonesia. Captain Cook spotted Australia and asked the servant if he knew what the name of the islands was, and he servant answered Au si ta lia, which meant "I can't see". I looked at my collection of the local languages of Indonesia and indeed in a few of these languages the word Au means I, ta means no and lia means see. It's purely coincidental of course and I imagine that it was either a group of linguists or Indonesians who discovered this similarity and fabricated this funny story.