Origin of the word 'Hindu'

[rajs at lugano.esd.sgi.com]

Recently I came across some discussion on the origin of this word - there appear
to be at least two schools of thought - one tracing the origin to the Sindhu
river (whose origin itself is also obscure) and the juxtaposition of 's' and 'h'
by the people who lived west of the river. The other school of thought traces
the etymology of the word to the Sanskrit 'hin' (violence) and 'du'
(without)(which, from prior postings to this group, appears a little suspect!).
Do we have any scholarly endorsements for either or yet another?

And while I'm on the topic, does anybody know the origin of the names
'Hindukush' and 'Hinduraj' for the mountain ranges west of the Karakoram?

Thanks,
Raj Sehgal