UKC

If you wanted to go from Sydney to Canberra to Melbourne to Adelaide by train, stopping off in each of those places,

a) could you?
b) how long would it take?
c) would it be fun?
d) what else should I think about?

OK, stopwatch on, let's see how long it takes the non-localised information repository/ fount of all knowledge that is UKC to answer this one

In reply to Tim Chappell: Sadly, one is lacking in train riding skils. One uses one's motorcar for transport. Given the foregoing, one ventures the following opinions: a) yes, but have been told that enucleating one's eyeball with a rusty nail is preferable; b) an interminable amount of time; c) unlikely unless you are of masochistic leaning and d) a disproportionately high cost compared to hiring a motorcar. Good luck.

In reply to Tim Chappell:

is it cheating to use a online map?
which seems to answer a (yes) and b (if you stick the numbers in).

http://www.railmaps.com.au/

In reply to Tim Chappell:

For d) fly to Perth, jump on the Indian/Pacific.

http://www.greatsouthernrail.com.au/site/indian_pacific.jsp

In reply to Tim Chappell: Would information on Bangalore to Delhi by train do instead?

In reply to Tim Chappell:
a) Yes-ish. There are no direct trains from Canberra to Melbourne.
b) You'll need a couple of weeks at least, the trains are not very fast.
c) Depends on your idea of fun really - most of Australia is not actually very interesting to look at, seen one temperate eucalypt forest seen 'em all.
d) Go to the U.S. and drive either the east coast and Appalachians or head across and explore the western half (Yellowstone, Grand Canyon & Yosemite trilogy a must.)

If you're going to do Australia you really need to cross the vast tracts of nothing by plane, the highlights are rather widely spaced here.

In reply to Tim Chappell:

If you're a train buff, the Indian Pacific and The Ghan are Australia's two big train experiences. Though expensive, especially with a strong $Aus. For Sydney to Melbourne look at
http://www.countrylink.info/

Sydney and Melbourne - enough interesting stuff to see. Personnally i wouldn't bother with Canberra or Adelaide, though you might have friends/specific things you want to see.

Would recommend looking into the climbing. Blue Mountains is within 2 hours west of Sydney, Mt Arapiles and Grampians within 4 hours west of Melbourne.