Most banks have processing companies that will put the homes on their websites as they process them. some handle only one or two banks, others handle many banks. There are several websites on my website that handle multiple banks, note that part of them handle hud homes as well and you have to sign up seperately for hud listings and for the bank owned listings on the site - http://www.yourstlhome.com under search for homes
The Banks and the Gov. maintain Databases of their properties for sale (REO/Foreclosure) for the public to use. These sites are well maintained, kept up to date and provide all the information on the purchase/bid process. Sites like these.....http://www.countrywide.com/purchase/f_reo.asp
You can find links to the Bank/Gov Databases and much more info here...
All Free All of the Time, Nothing to sign up For.......
Best of luck, Dunes