As I was curious how the leap-second of was handled, I dug into the manuals of NTP. To monitor all of this, I built (mostly copied from here) a script so that Cacti could create a graph to monitor offset, jitter and stability for NTP.
The leap second generated this log-message:
Jan 1 00:59:59 server kernel: Clock: inserting leap second 23:59:60 UTC
I'm not able to locate a source for the black and white Dilbert comics anymore. The one for yesterday will be the last. If I find another source, this message will automagically dissapear, but I think that the coloured Dilberts are probably the only ones left. The Dilbert website has changed also, it now has a browsable history back to january 1999, in colour. Soon this website will be obsolete.