The advantage over Ctrl-Alt-Down followed by Ctrl-X suggested by other users is that it doesn't make eclipse think that the file was changed in any way. It's also faster and causes no problems even if the user has rotating screen issue with Ctrl-Alt-Down/Up keyboard shorcut. So there's no need to remap shorcuts for this.
Another way to go would be hitting Alt-Shift-Up until the entire line gets selected. If you've gone too far, of course you can select less with Alt-Shift-Down.