The preferred RAM for Limewire is a bit over 2 MB. Last time I checked, it was eating over 50 MB on a dual-USB iBook with 384 MB RAM.

Hey, this is a handy app., but it's an internet client, not Photoshop. What is it doing with all this RAM and why does it steadily increase as time goes by (another old song...)?

It's not a memory, it's the overhead for the Java Virtual Machine.

So basically, the Java VM is like an emulator that eats a proportion of your available RAM?

Yes, it's sort of an abstraction layer between your operating system and the Java program. The problem is, that the JavaVM is a little bloated and slow, although Sun's latest JRE 1.4 (which will not be available for Macs in the near future) improves that greatly.