...the number of [...] fake pings--"spings"--has also increased...

--Blog firm working with Google to cut 'spings', vnunet.com, 10 February 2006

The wikipedia entry on sping says the word is short for "ping spam," and notes that spings are sent from "splogs," or spam blogs (which are blogs in which the content of the entries themself are spam; an explanation of what web spam is and why people do it is beyond the scope of this entry).

I'm amused that the Wikipedia entry for "splog" describes the term as a neologism, apparently without noticing that "blog" itself is a neologism.