Martin has posted a nice entry in his blog “programming kung fu” about eclipse hot keys.

I think the most important key is ctrl-shift-L which gives you a list of all shortcuts. A shortcut I often can not remember, when I am searching for a specific one. So it is also one used very rarley.

Beyond the common ctrl-C/X/V/S/W and the ones mentioned in the article or the comments, the shortcuts I use most are the following:

alt-up/down - For moving the actual line / all marked lines up / down one line.

alt-shift-up/down - Duplicate the actual line / all marked. This one is very cool in combination with the one above, when hacking configuration with many similar keys.

ctrl-D - For deleting the actual line. Very useful when you have used the two above too much.