After writing a script to clean up my Zeitgeist DB (not deleting events), optimizing an FTS issue and vacuuming, my 2 Zeitgeist processes now uses around 12 MB with normal usage (logging everything and using Synapse) and Docky... I will look into the 64 Bit issue soon, but with 32 Bit I hope this stays constant for a while.

I will blog more about this experience soon...