Also a note, I haven't tried it yet, but the qqdbus package in -devel purports to contain a Maemo-friendly version of QDBusViewer, which allows you to browse the 'Bus, and should help you with this sort of thing. Note that you'll need to install Qt 4.6 from -devel for that (AFAIK), so you may just want to wait for PR 1.2 to avoid Fun with the update. Alternatively, you could probably build QDBusViewer from the Qt 4.5 source packages in Extras, but the stock UI is a bit painful on the N900's screen.