Thanks jimmij, thats definitely better than nothing. Permanent line numbers on a bar to the left would have been better though :)

There is always the Eclipse plug-in if you need some of the more advanced features of a IDE.

Advanced feature? I can display line numbers in my favorite text editor (SciTE), but I never do that. I never felt the need since I stopped to code in Basic (goto 20). I can get the current line number and jump to a given line number, that's all I need.
In the Web, line numbers can be useful to refer to a given line, but that's all.

@phi.lo its not a real urge but I prefer having the numbering as an additional visual anchor. For example to know, "oh you've 'hit the 200 lines, time to split the classes", and to avoid situations like "hmm, theres a compiler error at the line 129...hmm must be somewhere around there...". I guess It's a matter of personal preferences. Some people fins id extremely cool to type on blank a Das Keyboard...

@jeff_g yeah, I prefer not to code in PDE, and for regular processing stuff I don't, but I still have not figured out how to export a .apk to android. And as there seems to be no comprehensive tutorial or example project out there, I'm stuck to PDE...

Feel free to provide guidance for Processing/Eclipse/Android intergation. I have found http://forum.processing.org/topic/presenting-to-android-phone-from-eclipse but it didn't help much, as the apk I exported does not install on android.

My answer was probably a bit clumsy. It wasn't a judgment on your need, but rather a genuine question on your usage.
My curiosity is satisfied...
Now that I think of it, the DPE doesn't have a "Jump to line" feature, so it is doubly lacking... (although usually we don't make super-long code, or we split it between tabs).