Lots of companies offer unlimited bandwidth, but there are usually get out clauses in the terms and conditions you agree when signing up for such a service.
If there were hosts offering unlimited bandwidth for just a few dollars per month, don't you think that yahoo would use them?
Common get out clauses are,
Unlimited bandwidth ( as long as the several websites sharing the server do not use so much bandwidth as to slow down or crash the server ).
Not allowing certain files to be uploaded, like php, certain graphics, graphics which are a certain size ( basically by doing this, they know your never go over the bandwidth because you are virtually forced to use text only web pages ).
Only allowing you to upload to the server in a given time ( one a day , or even one a week or month).
Strict regulation rules that are almost impossible to break ( once your bandwidth gets fairly high, they just close down your account and tell you the reason is you broke rule 12b.. ).
However this does not mean that all hosts offering unlimited bandwidth are bad. Some just find it a better marketing advertisment and give you a fair amount of bandwith. Most new sites wont go over 3 gigs a month. And if you use too much bandwidth the good companies will email you and tell you to upgrade your account without closes down your website.
On the other hand... most terms of service agreements have lots of get out clauses... this is just the legal way to write such terms.
My advice is to search the forums and ask others advice on popular hosts. It is slow and will take a while to gain knowledge but eventually your find a decent host you can trust. Search other websites as well as this.
Thats the whole point of hosting directories and hosting forums, to help you make the best decision possible when choosing your host.
Good Luck
