Eclipse memory analyzer eclipse.org/mat/
DTFJ adapter for IBM VMs ibm.com/developerworks/java/jdk/tools/mat.html
Wiki wiki.eclipse.org/index.php/MemoryAnalyzer

Chapters (these work best in Chrome using the HTML5 player)
The chapters prefixed with MAT show examples of using Eclipse memory analyzer.

Definitions 2:54
Retained heap examples 4:50
Understand memory usage 7:17
Dominator tree 8:00
Parent retaining child 8:53
MAT / Dominator tree 9:10
Class Histogram 17:30
MAT / Class Histogram 17:56
Inspect clumps 23:34
Reains 24:46
Extras 25:20
MAT / Group by value 25:48
MAT / Collections grouped by size 27:28
OQL 29:18
MAT / OQL 29:36
Links 32:50
MAT / Group by value 33:16
Thanks 34:41