Other than investing in sundry international equity funds, is there a way for an Indian citizen to invest in global securities? Is it possible for example to buy shares of Google?
You can invest upto $200K per year abroad, and yes, you can buy Google as a stock. Consider opening an international account with a broker like interactive brokers (www.interactivebrokers.co.in) which allows you to fund the account from your local Indian account, and then on, buy shares of companies listed abroad.
It isn't just ETFs, you have normal mutual funds in India which invest internationally. This could be convenient if you don't already have a depository account and a stockbroker.
Here's a list of such funds, along with some performance data: Value Research - Equity: International: Long-term Performance.
However, you should also be aware that in India, domestic equity and equity fund investing is tax-free in the long-term (longer than one year), but this exemption doesn't apply to international investments. Ref: Invest Around the World.
There are some ETF's on the Indian market that invest in broad indexes in other countries
Here's an article discussing this
Be aware that such investments carry an additional risk you do not have when investing in your local market, which is 'currency risk' If for example you invest in a ETF that represents the US S&P500 index, and the US dollar weakens relative to the indian rupee, you could see the value if your investment in the US market go down, even if the index itself is 'up' (but not as much as the change in currency values).
A lot of investment advisors recommend that you have at least 75% of your investments in things which are denominated in your local currency (well technically, the same currency as your liabilities), and no more than 25% invested internationally. In large part the reason for this advice is to reduce your exposure to currency risk.
Other than the possibility of minimal entry price being prohibitively high, there's no reason why you couldn't participate in any global trading whatsoever. Most ETFs, and indeed, stockbrokers allows both accounts opening, and trading via the Internet, without regard to physical location.
With that said, I'd strongly advice you to do a proper research, and reality check both on your risk/reward profile, and on the vehicles to invest in. As Fools write, money you'll need in the next 6 months have no place on the stockmarket. Be prepared, that you can indeed loose all of your investment, regardless of the chosen vehicle.