I would love to extend Beagle to use Avahi to advertise beagle running on a workstation, and allow other computers to search its indexes in a fashion similar to music sharing in Rhythmbox.
June 26, 2006:
Avahi service discovery implementation complete. Design completed for
remote message passing interface, and partial implementation.
August 21, 2006:
Message passing interface completed. Holmes extended to perform remote
queries and fetch data from remote hosts.
Authentication would be comprised of a cryptographic challenge/response system using pass-phrases and keys. Once two nodes have been paired up, they will automatically talk to one another when they are on the same network. A "Sharing" or "Network" tab could be added to beagle-settings, which would allow the user to enable searching on the local network, and sharing local indexes with other computers.
When beagled finds another host sharing its indexes, the user would be notified, and given the opportunity to perform an initial authentication. If the automatic notification is too annoying, then the user could have some means of finding other computers to pair up with. Beagle daemons on remote machines will communicate via XML-RPC.
When searching in beagle-search, a query is sent to beagled, and beagled forwards the search to any hosts on the network that have been authenticated in the past and are currently available with shared indexes. Any nodes that require no authentication will automatically be searched.
For live queries, any nodes that leave the network or are no longer available will be removed from the results. Any new node that becomes available during a live query will be sent the query and any results will reported. Remote Beagle daemons will treat these live queries just like a local live query on that machine, and will send new results to the node that made the initial query until the remote live query ends, or the node that made the initial query becomes unavailable.
Any remote hits will be displayed in such a way to indicate that they are from a remote machine. They can also be hidden by a disclosure triangle, and will only be shown if there are available results. For example:

Double clicking on a hit from another computer might be tricky. Maybe using HTTP to download the file from one host to another. The file could either be copied to a /tmp directory, showing some progress dialog until it is copied and then opened, or just using GnomeVFS. It would also be useful if the user could also drag and drop any remote results to a nautilus window or the desktop, which would copy it to the local disk.
The original webservices implementation for Beagle only handled file queries. It would be interesting to find a way to handle remote chatlogs, webpages and emails.
I am finishing my third year of undergraduate studies at California State University, Sacramento, where I am majoring in Computer Science. I've been using GNU/Linux on the Desktop since 1999, and am passionate about free software. See my resume for more information.
As for my .NET experience, I have been using Mono since its 1.0-beta release, have been loving it ever since. I used Mono to develop several in-house Gtk# applications at work, and a charity raffle system for a large annual charity event in California.
As a casual GNOME contributor, and a Beagle user since 0.0.[89] ish, I would love to have the opportunity to hack on Beaglefull time this summer. Beagle is one of the most interesting components of the GNOME Desktop, and I would love nothing more than to help make it more useful for the community.