Librarians (rightfully) have their doubts about swickis. So far the only swickis I can find are all by eurekster -- all from one corporate source. But I think they have potential, and I like them because they can be built, trained, and customized. You can tell your swicki which sort of sources are better for the searches you run. You can suggest better sites, and demote sites that return poor results -- which could make for a sort of "dumb" expert-systems type of a.i. in an a quickie-wiki, stop-gap sort of way. So I think they have potential -- but they need lots of TLC to make them work well. The big question is: is the amount of time and work you have to put into them worth the results? I wish I knew. But there's only one way to find out, and that's to invest the time and see what they can do.
Over at LISNews there's a post with a link to one of the three swickis I've built: "archival swicki"... and the name is a bit misleading. It's meant to be a search portal "for hard to find texts, images, audio, art, public-domain images and information, electronic books, and archival media," not just archives per se. I built it because I couldn't find a good, single search engine for all of these kinds of resources. Archive.org comes closest -- but it leaves out lots of the museum-type stuff and obscure manuscript facsimile type stuff that I want included (archive.org is included in the list of sites this swicki looks at first, though).
Another is the ISHUSH swicki, which is supposed to look for "technology, magick, media, information science and libraries, and artistic and cultural innovations, at least." This was the first one I put together, and is more of an experiment, less of a good focused searcher I think -- but it's got it's own uses, and is meant to hunt that, you know, certain kind of meta-informational fringe-technology occult historical library science stuff.
Finally there's the Spime Watch, for info related to 'ubiquitous computing', spimes, kirkyans, RFIDs, folksonomic indexing, etc.
If you have a chance and have the need, take these for a spin and see how they do you. If you're working with LIS type swickis of any sort (or swicki-type search engines that have nothing to do with eurekster, even), I'd like to see them.
Reading: Rupert Murdoch's MySpace
Listening: The Postal Service (thanks to April and Brad, each).