I don't know if this has been discussed here yet, but I am getting hits from the bots from http://www.picsearch.com
They seem to be behaving themselves but I am interested in them as they seem to be keeping a low profile, and are images only. So it is a bit of a different story to full text search.
I was wondering if anyone has looked into their algorithm, or tried optimisation or anything.
I'd also be interested to see what people think of it as an alternative to google + yahoo's image searches. It definately seems faster...