Eclipse Configuration settings

Values to add to your Eclipse.ini file.

Add -Xverify:none to your eclipse.ini.
It will cutdown your eclipse startup time considerably (50% in my case if not more). This will tell the VM not to validated all the .class files it is loading.

See also http://stackoverflow.com/questions/142357/what-are-the-best-jvm-settings-for-eclipse/3275659#3275659

For these:

-Xms128m
-Xmx2048m
-XX:+UseFastAccessorMethods

Use JDK6

The JDK6 is now explicitly required to launch Eclipse:

-Dosgi.requiredJavaVersion = 1.6

Use JVM.dll

The dll jvm.dll is a Java HotSpot(TM) Client VM.
 Aledgedly Eclipse runs better when linked to a specific dll:

-vm
<Path to JDK>/jre/bin/server/jvm.dll

A desirable side effect of this is that if there are any problems with Ports the fire wall will now report "Eclipse" is requesting to access ... sooner than "Java".

Preferences 

The best way to monitor the current memory useage in Eclipse is to enable HEAP monitoring:

Preferences --> General --> [x] Show heap status.

Another performance boost can be gained by disabling label decorations (Windows -> Preferences; General -> Appearance -> Label Decorations) and by disabling unused capabilities on startup (Windows -> Preferences; General -> Startup and Shutdown).