 <p>As a lot of people have suggested, Resource Leaks are fairly easy to cause - like the JDBC examples. Actual Memory leaks are a bit harder - especially if you aren't relying on broken bits of the JVM to do it for you...</p> <p>The ideas of creating objects that have a very large footprint and then not being able to access them aren't real memory leaks either. If nothing can access it then it will be garbage collected, and if something can access it then it's not a leak...</p> <p>One way that <em>used</em> to work though - and I don't know if it still does - is to have a three-deep circular chain. As in Object A has a reference to Object B, Object B has a reference to Object C and Object C has a reference to Object A. The GC was clever enough to know that a two deep chain - as in A &lt;--> B - can safely be collected if A and B aren't accessible by anything else, but couldn't handle the three-way chain...</p>