To search for Fannie Mae properties anywhere in the country, you can visit www.homepath.com. 

For additional information about Fannie Mae properties see:
Fannie Mae First Look
Homepath Ready Buyer (TM)

To search for HUD properties anywhere in the country, you can also visit www.hudhomestore.com. 

Also check out this other helpful information:
GNND Program
203k Financing Program
HUD Information