what would you do with 100k

Buy a house by a college/university, it's by far the best option. You will always be able to find people to rent, always, even if you are stuck giving a small discounted price. You'll be extremely pleased in 15 years when a house you put a $20,000 down payment on is now paying you back at least tenfold. I'm a 22 year old university student who will be doing this by the latest September 2014. If I can find a partner, then by September 2013.

30 year >>$1800 mo P+I, tax, ins 

3 units >> $1,200 unit >> $3,600 >>+$1,800  

2 units >> $2,400 >> rent free +$600