I've updated my extension to resolve LSIDs in Firefox so that it works with version 22.214.171.124 (the most recent version of Firefox). The extension is available from Mozdev. It may take a little while for the mirrors to update with the new version, so if you get a "404" when trying to download, you may need to come back later.
IBM's LSID project have their own Firefox extension LSID Launchpad for Firefox, which is a lot slicker than mine. It's in beta, but well worth a look.
In case you're wondering, these extensions enable you to browse LSIDs as if they were URLs. For example, with the extension installed, a LSID such as urn:lsid:ubio.org.lsid.zoology.gla.ac.uk:namebankID:10386 becomes clickable, and you can see the metadata associated with the LSID. For the technically minded, they add support for the lsidres protocol to Firefox.