Al Gore is putting his wallet in the balance and starting a new Earth-friendly investment fund. You've heard of market timing, sector investing, cyclical investing and even "socially responsible" investing - no alcohol or gambling stocks in the portfolio, for example. Heck, there's even "sin" investing - only alcohol, tobacco, adult entertainment and the like in the portfolio. Now Al Gore wants to introduce you to "sustainable investing" - but ironically, only if you're among the group of the "wealthy" from whom Gore fought so hard to keep tax breaks. Seems the former veep, along with some well-heeled partners like...