I woke this morning to find that overnight someone had sent a lot of trackback pings to this site for a seedy and pathetic site claiming to have lots of photos of various 'celebs'. For some reason this got past the filters. It's now been cleared.
I have no clue why this happens periodically, a simple glance will show that any links do not persist - and also that linking is not direct, therefore going to that effort will not improve google rank of the linked page. (I know that once on lists, these things keep happening, however someone must have originally spotted the site and listed it).