Shepard's Citations via LexisNexis Academic  Available in the law library to the public. Available remotely with a CSU ID and Scholar PIN.
Casemaker  has a case check feature. When you pull up a case, it will list cases citing the case you pulled up. Law school users have Casecheck Plus, which will indicate the cases with negative treatment and provides each case with a signal indicating whether it has subsequent negative treatment. Casemaker is accessible from the public access terminals in the law library, or remotely to OSBA members.
Fastcase  also has Shepards-like features.
Google Scholar - When you pull up a case, click on the "How Cited" tab. Under "cited by" is a list of cases that cited to the case in question. There is also a list of "Related Documents", which are cases and scholarly articles, most likely retrieved according to an algorithm.
Revised, SA 11/2011