After dumping thousands of files to N900, media tracker was making my device unusable for a few minutes after startup.

But lo and behold, we have complete control of behavior! God Bless Gnome, God Bless Nokia

vi /home/user/.config/tracker/tracker.cfg

I just started playing with it, so i don't want to advise on any specific changes.

Just check it out, make a backup and pay attention to where you put your media.

You have the power!