Each bank has different criteria regarding short sales, so the best place to start is probably your bank and find out what their policies are. Depending on whether or not you have to be "behind" will determine how much your credit gets "dinged" and since you don't know the bank short sale policy, it is impossible to say how this will affect you in the future. A couple of things to share, though:
If you have more than one mortgage on the property (even if it is held by the same bank), the first mortgage holder can agree to whatever number they want, but the second mortgage holder is going to get nothing and will hold you liable for the deficiency.
There is also something called a "deed in lieu of foreclosure". Basically, you hand your house back over to the bank and move out. Again, each bank has it's own criteria regarding this process, and you may or may not have to be behind on the payments to qualify, but it may be an option. However, if there is a second mortgage on the property, you will likely be held responsible for the deficiency.
Loan modification - you will have to check with the lender to see if you qualify, but I have seen people get an adjusted interest rate that is rock bottom for a fixed period of time to help them get ahead a bit on their house. I know it is too small for you, but might be an option until the market turns around and the house gains a little more value.
Foreclosure - I don't deal with your state, so you need to do some checking, but my understand is that it would take about 1 year to foreclose on your home. So, if you stopped making mortgage payments today and put them in a savings account, you could possibly live "rent free" for one year. Your credit is going to be in tough shape, but you will have one heck of a down on a different place which is likely going to overcome that issue. Again, if there is a 2nd mortgage on the property, they are going to hold your responsible for the deficiency.
Rental - if the property is small, it may appeal to a different family that is willing to rent. Make sure that you do background checks, do your legal legwork on lease agreements, and follow all the rules regarding holding deposits if you decide to rent it out.
Good luck!