What resources do colleges and Universities have to find out if you've
attended college elsewhere and have transcripts you have not submitted
to them?  For example, if someone took a semester of college at one
college and failed out then, a couple years later, went to another
college and told them that they have never attended any other colleges
so that his grades do not suffer.  Is there any way the second college
could find out that he really did attend another school and that he
failed out?

Thanks

In my experience, colleges aren't going to do random searches like
this, because transfer requests usually involve a fee, and would
require the written consent of the applicant. If you want credit for
previous courses you have taken, you would need to provide this
information. But, if you don't want any of those classes transferred
over, that's your prerogative.

The only exception might be if you are trying to apply for some sort
of scholarship through the university in question.

It's possible for colleges to find out (though I don't know how.) See
http://snipurl.com/lxsf for a recent example.