Richard Cyganiak pointed me to this one, perhaps we find something there that can help us doing updates on graphs. but which code snippet? hm

http://rdqlplus.sourceforge.net/doc/ridiql.html

RIDIQL (RDF Insertion Deletion Inspection and Query Language) builds several utility commands on top of RDQL to make working with RDF graphs easy. This reference describes each of the commands and gives examples where appropriate.
Note: All commands may be written on multiple lines and are terminated with a ; character. Command names and tokens are case-insensitive, but when written in this reference, they are capitalized for clarity.

http://rdqlplus.sourceforge.net/doc/ridiql.html

Doug Cutting writes about a web-services / desktop mixture that i like.

In this web-based world, I'd like to keep all my personal data remotely, so that I can access it equally well from a Linux workstation, an Apple laptop, a Palm phone and a Windows-based internet-access terminal. Still, I'd like to leverage my local resources. For example, my laptop and handheld should be able to access my data while offline, and my workstation should be able to search it quickly using a local database.

could gnowsis be the glue? not by his arguments against java, but we are scientists, leave it to the corps to do the dirty c hacking.