What could you do with 41 Million Dollars?
- Hire 5 full time employees: Two great programmers, a really good artist/designer, a veteran sysadmin, and an insider with skills and connections in the appropriate industry.
- Pay them an average of $100k each.
- Buy enough hardware, hosting, tools, etc to scale (let's say $10k/month).
- Rent a nice office for $2500/month.
- Buy an incredible domain name for $250,000.
- Pick an idea from 37signals' "Bootstrapped, Profitable, and Proud" list. 
- Build, pivot, and iterate non-stop for a year.
I think, at the end of the year, if you picked your team right, you'd have a pretty good shot at a profitable business. And if it fails? Well, good news, you can do it all over again. 40 times. And still have $5 million left. 
 Actually, I'd fund my current startup (launching in April), or maybe scale up one of my existing businesses first. Your idea doesn't matter as much as your team, but if you don't happen to have a good idea already, you could do a lot worse than building a competitor to an existing, profitable business.
 More than enough money to give seed funding to every Y Combinator startup since 2005.