OK, I posted something about this at:
http://forumz.tomshardware.com/hardware/modules.php?name=Forums&file=viewtopic&p=626487#626487
To rewrite it,
OK, after doing some research (that's what the net is for!

, I've enlightened myself on the subject of pencils, in particular about their electrical conductivity. And I would like to share that enlightment with you, if you don't mind.
First, pencils don't have lead (Pb) in them, it is graphite. All the same, because graphite is a form of carbon, and it conducts electricity.
As to what type of pencil to use when connecting those L1 bridges... from this site
http://teenwriting.about.com/teens/teenwriting/library/weekly/aa111700a.htm?rnk=r1&terms=pencil (read the bottom list), I would say, the softer the better. The softer the pencil, the more graphite comes off it.
The higher the x in "xB", the softer the pencil is. The site says that's in European rating, but. I don't know what the rest of the world uses, but well, look for the softest pencil!