Ever wondered about regular “out of memory” crashes of Eclipse? One solution for you might be to set the Java Virtual Machine settings in case you use sun java (on linux)
eclipse -vmargs -Xms1024m -Xmx1024m  -XX:PermSize=256m  -XX:MaxPermSize=512m

(Thats rather pessimistic numbers, but my computer has 1,5 GB memory, so I can afford it.)

The problem seems to be that suns virtual machine is not reserving enough permanent generation space and can not handle big amounts of loaded classes. More detailed explanation you can find in my excerpt (in german language) Java Virtuell Machine Setzungen für große Serveranwendungen anpassen
“The permanent generation is used to hold reflective of the VM itself such as class objects and method objects. These reflective objects are allocated directly into the permanent generation, and it is sized independently from the other generations. Generally, sizing of this generation can be ignored because the default size is adequate. However, programs that load many classes may need a larger permanent generation.”( Frequently Asked Questions
about Garbage Collection
in the HotspotTM JavaTM Virtual Machine).
See also jmap – Memory Map, Eclipse Bug 92250.

A great explanation you can find at Frank Kieviet’s Blog:

More Virtuell Machine (Hot Spot) options at http://java.sun.com/javase/technologies/hotspot/vmoptions.jsp and tuning tips at http://java.sun.com/docs/hotspot/gc/.