Teerio - what's your address and loan amount?
And what's your current employment/living situation?
And how are you getting your value estimate?
And what index is your adjustable mortgage tied to? Most indices are lower vs origination date, your payment could easily be going down...
Our local market wasn't even this hot back in '05, I really feel like you're using outdated information to base the amount your upside down....
If you follow through on a short sale, more than likely missing mortgage payments along the way, you'll effectively be locked out of purchasing another home for 3 yrs, only 2 yrs if you have 20% down.
You need to sit down with a loan officer to help with the above questions, and I'd be honored if you considered me.
Please let me know if I can be a further resource for you!
Best of luck, Jeff