You can also set the note up and then gift your children "fractional interest" of the note.

If you were gifted an elf that could tackle only one job, what would you have the elf do to reduce your work load the most? 

And Google "how to hack home depot gift cards" to save more money buying Home Depot cards and using them to pay for the purchase for additional savings.

I decided to gift the house (just the house) to the fire department.

You could give these folks a gift card or gift basket of some kind.  

You could make the models and keep a trophy of your portfolio or offer them as gifts to homebuyers.  

By property #5, you'll need a 720 and extra assets (down payment minimum increases, reserves increase).A thing to note here is you can't get an investor down payment on these- no gifts or seconds on a investment purchase.

Gave it to my wife as a wedding anniversary gift in 2013.

I heard that there is a life time gift exemption of $5,250,000 in 2013.

This is a highly complicated area of law that I could talk intricately about for quite some time, but it would do you no good as Family Law and related aspects there-of are almost entirely local.