I got the chance to demo a new take on search two weeks ago. Jeteye has released a solution that actually makes search results persistent shared spaces, called Jetpaks. Jetpaks are hosted by the company, and can be shared with the world or with a specific group of people.
When you enter a search term into Jeteye, it uses any of various search engines (like Google, Yahoo, and so on), but also searches against Jetpaks that you have access to. You can also create new Jetpaks based on these searches.

New links, tags, and commentary can be added over time by people with access to the Jetpak. So we can imagine -- given a bit more sophistication in the sorts of elements that can be added -- that a Jetpak can be a shared space, one element in distributed collaboration.
People can be 'invited' to the Jetpak via an integrated email invitation approach. Public access seems to also be implemented via simple URLs, as well as searching across public Jetpaks. Try searching for "stoweboyd" and you'll find several Jetpaks that Jeteye folks and I have created while fiddling with the technology.
Jeteye represents the fusion of search and bookmarking, providing a single toolset for adding links to existing Jetpaks (a browser plugin) as well as a search capability (albeit piggybacked on the other search engines) to find new stuff. This fusion is inevitable -- which is why Technorati, del.icio.us, and other search-related applications will be sucked up by search engine companies. Likely end game for Jeteye, too, I expect.
In practice, I have encountered the usual beta glitches, and barriers to practical use. For example, I created a jetpak just for sharing with a small group of colleagues, and I wanted to include a link to a Basecamp project. Basecamp encodes URLs with 'https' -- secure HTTP -- and Jeteye barfed on the link. But even if it hadn't, Jeteye would need to then store the login and password for the Basecamp instance, for this to work. A likely scenario for effective sharing, but a snag at the moment. Also, I have trouble updating existing Jetpaks -- little things like editing tags -- and while it may be operator editor ("read the manual, dummy") the user interface is not all that intuitive at times.
Interesting to bump into technology that is directly implementing metaphors I have been using, like "tags define a shared space". Here, the metaphor is search as a shared space. In practice, we very commonly tell people to look something up on Google, then to do something once found. Now, we can collate a single web location with commentary, or collate a number of unintegrated bits of information together into a portfolio or dossier.
Once some more capabilities are added and the rough edges are smoothed off, Jeteye could potentially represent a radical alternative to conventional notions of collaboration. I could use a collection of very specialized tools for various things -- calendars here, spreadsheets here, project blog there -- and collate these along with web links, comments, and the like. Jeteye could become a meta-collaborative tool, sitting above more specialized systems, pulling the bits and pieces together, and creating a context for sharing those bits. Very cool stuff.