Install JadClipse

You need it seldom, but it's nice to have one: a Decompiler.
JadClipse is a plugin for eclipse to implement jad into the Eclipse-IDE
First you need to downlod jad (1.5.8g) and JadClipse (i took JadClipse 3.2.4 for Eclipse 3.2).
Extract the downloaded jad*.zip to your preffered location.
Copy the downloaded net.sf.jadclipse_3.2.4.jar to your eclipse plugins directory and restart Eclipse with the -clean parameter (on windows: eclipse.exe -clean).
Go to Windows --> Preferences --> Java --> JadClipse and check the "Path to decompiler" that it points to the Jad-Executable (on windows: jad.exe)
Next check the File Association of *.class files under Windows --> Preferences --> General --> File Associations that they point to JadClipse.
Have Phun :-)