First you do not have to sign-up to qualify for the stimulus money.
You must close on a home before Nov. 30, 2009 to qualify. Close means to buy the property and pay for it with cash or loan.
So if you find a property and write a contract to buy it and get the funds through a loan and pay the seller before hte 30th of November you qualify, (if you have not owned a home in the past 3 years).
A mobile home does qualify as a home and you would get the stimulus money.
If the mobile is bought at $33,000 you would qualify for $3,300 (10%) stimulus money from the qovernment.
I recommend that you check out buying a stick built home because it is possible to get a loan with little or no money down. This may be a mush better investment than the mobile home.
You do not have much time - call a realtor and find out what you can buy in your budget.
Don't delay, it is important that you act now!
Hope this was of some help, good luck.
Y City Realty
And to help clarify what another poster answered...
A Rural Development loan will let you buy a home with no down-payment, however you can not purchase a mobile/trailer or manufactured home and it must be outside of the city's corporation limits (you can find that by Googling the USDA Property Eligibility Disclaimer site and enter the address).
It is similar to a FHA loan but the FHA loan still requires you have a down-payment. I don't know much else about FHA though, because I have an RD loan, not FHA. :)