PsycInfo (Psychological Abstracts) includes bibliography information for recent articles in its database. As a result, you can search PsycInfo to find citations to a particular work.
To do this, go into PsycInfo and choose Cited References in the tabs along the top of the search window.
The next page will allow you to fill in the Author, Title, and Journal/Book Source of the article you want to find citations to, as well as general keywords or a date:
Click Search to have it hunt for your original article.
From the list of articles it produces, click on the check box for the one(s) you are interested in, then click the Find Citing Articles button.
Note that for each article on the list, there is a "Times Cited for this database (#)" if the article appears in any bibliographies of articles in the database.
The Citing Articles list will display and work just like a normal PsycInfo search.