Keep that cash.
You could start a wholesale real estate business. To wholesale houses, you find old run down properties, get a contract for way below market, then sell the property for $3,000 to $10,000 ( sometimes more) than your contract price. You don't actually buy the house, or need to get a loan or do any fix up. You rarely need to invest more than $10 to secure the contract.
Because you have limited time to find houses yourself, you can run an ad on craigslist to recruit people to find houses for you with the agreement that they will be paid $1000 for every house you buy.
If you just do 1 flip deals per month, you'll make more than many people make working a full time job.
I can share more details if you are interested.