Are you carrying PMI? Depending on the insurer, there may also be options available to you, but you won't know unless you take the initiative and let them know you are willing to step up and get to work. Hiding out, avoiding phone calls and letters will really hurt you. The lender then has no recourse but to foreclose.
Now, if you resorted to a national lender, perhaps someone on-line, your options will be more limitted. Large corporations have page after page of protocols they have to follow, and it it really hard to get them to stray from the script, even if you CAN actually speak to a human at some point.
The advice to get a good attorney and accountant is very good advice. Contact me if you need a referral in that area. I have names in north county of professionals whom I trust. I hope this helps.
In general terms, a foreclosure will keep you from buying another house for 5-7 years--a bankruptcy is 7-10 years. A short sale, done correctly, with prompt and proper credit repair actions begun immediately, could have you back into another home purchase within 3 years.
There have also been numerous incentives offered to lenders to encourage both short sales and loan modifications, both of which are dependent upon your financial situation as the homeowner--they will require the same kinds of paperwork which was required to obtain your loan:
bank statements for 2 months
proof of income for 2 years
as well as a Hardship Letter, which explains why your financial position has changed.
These are just a few general rules of thumb--you should consult a tax professional as well as an attorney who specializes in foreclosures or bankruptcy to get the complete picture and all ramifications.
Good Luck! Hope this helps.