I'll look into the reference option thanks Geert...
As for speed in general, I have my iPhoto library also on the NAS. It's certainly a trade off. On my wired gigabit connection the lag is noticeable but doesn't bother me as much. I'd much rather have them on a RAID NAS then any other way. Again certainly external (firewire) backups are more responsive. It depends on what you need. I'm an ambitious point and shoot snapshot guy (can one even call that ambitious?). My main concern is safety. All I do is store, look at on desktop, print/send out for calendars and slide shows for family. The occasional lag does not bother me.
On the other hand if you WORK with pictures or do a LOT of manipulating than storing the library is certainly a NO GO.
Just my two cents worth...
Cheers,
Philly


