I suppose the short answer to 
that question is - they all do.
Some require more expertise 
than others - some require
investment of money, others 
investment of time and yet 
others require both time and 
money. Most also need good 
advisors.

For someone with a lot of cash 
and no real interest or time,
term investment with a fixed 
interest rate may make sense.
Returns on this vary greatly so 
best to do your homework on best
interest - do watch out for the small print though so you
don't get stung with high management fees.

If you love scanning stock markets and have a good grasp of how
it all works, plus a few inside friends who can help you to get
in early on markets - that could well be a very lucrative
investment proposition for you. You can also go through a
stockbroker who will invest money for you. As with a lot of ways
of making money you will need some capital or equity in
something to get started. The more you invest the more
widespread and stable your portfolio is likely to be.

Investment property also requires capital and some knowledge of
the property market. If you have the time to go out yourself and
look for properties which have a good chance of appreciating
well either long or short term, this may be the bricks and
mortar venture that appeals to you. There are also companies who
will find property for you, usually for a percentage on top of
what you pay for the places themselves. From the point of view
of tax incentives and negative gearing property may be the best
bet but even then you need to have a competitive enough mortgage
rate to make the whole prospect viable.

You may decide that a government housing scheme sounds the most
stable and steady course. Most state governments have housing
projects in which you can invest - ask your local council for
details.

Other investment opportunities include buying fine art to be
then rented out to clients wishing to decorate their office
space. You will again need quite a lot of capital to do this but
if you are an antiques or fine art fancier this may well appeal
as a way to finance your hobby and increase your collection.

You can invest in your own business - if you have enough money
available you can buy a franchise with one of the big companies.
There are some excellent business systems which include real
estate, stock and all the training necessary to make your
efforts guaranteed to succeed. If money is not as easy to come
by you could invest in your own ideas - be careful to research
the market and make sure that there is room for such an
innovative step - remember that only one of of five small
businesses are still in existence after two years - meaning a
lot of time and money wasted. A third option would be to follow
one of the many systems available to build passive income.
Usually the financial outlay for these is not exorbitant and
with companies that have been in business for more than 10 years
there is training and support both online and one-on-one to help
you succeed. Working for yourself can be incredibly rewarding
while demanding a lot of your time when you are starting out.

Whatever financial backing you have available there are usually
many options. As with so much research in this day and age, the
web is a fabulous source of information and advice.