Sob! This doesn't work - at all - on eclipse 3, fresh virgin install with JDT etc. It apparently *only* works on Eclipse 3.0 M8.
So...now I'm still looking for a tool, but hopefully one that *actually works* and isn't Eclipse-2 only (which would make me very sad having just spent more than 3 fscking hours getting eclipse 3 to work just to try and use this tool).
EDIT: Ah, actually, one of the developers cleverly disabled the only documented way you could enable the metrics. There is also a bug so that the the secondary method doesn't work in 2 cases out of 3. Eventually, mainly through pure luck, I discovered the one way of getting it to run (although all the documentation on the site, and in the plugin, is wrong and won't work if you try and follow it).
Unfortunately, for no apparent reason, the dependency graph never works. So, I'm still looking for a tool that works
EDIT2: The same developer has hard-coded the dependency graph to be windows-only. What a moron! He writes a java-tool plugin for a java IDE in java, and he hardcodes it to only run on MS-windows. And despite admitting to that mistake 3 months ago, he hasn't got around to fixing it.