The Open Search Engine Initiative Spider
 

Has anyone noticed this User-Agent in their logs?
Exact String:
Mozilla/5.0 (compatible; MSIE 6.0.2090; The Open Search Engine Initiative Spider -- Coming Soon)

The IP address resolved to an ADSL user at SBC Internet Services (PacBell)

More than likely someone spoofing their UA with Firefox - its a good way to see cloaked pages :)

grub.org used to do something similar.

There are quite a few distributed search spider programs -- almost like a peer to peer search engine that crawls the web and submits indexes to some master site. Looksmart sponsored grub and then shut it down a while back.

I would bet this is probably a spider related to Peter Nordin's work. (His name came up in a google search and he has quite a few peer reviewed distributed projects under his belt)