Have you ever thought of a synchronize feature for DT?
Detour: a short story about Safari and OmniWeb. Safari is a great browser. Fast and slick. But I like OmniWeb more because of several unmatched features like the html editor (which is btw great to clean up web content before import to DT). Nevertheless I use Safari all the time because it has a really great bookmark synchronization. Using three Macs - one at the office, two at home - it’s a real pain to keep all bookmark data bases in sync, but Safari gets the job done.
So… I also use DT on my three Macs, but to sync the data base thats what I do right now: keeping all new entries in one group, exporting this group from time to time to an iDisk folder and importing that to the other ones. It works this way… alas, I’d love to see more comfortable means 
What about a one click, one shot sync feature for DT? Would be a terrific addition to an already great product.
Why don’t you just copy the whole DEVONthink folder (usually located in the directory ~/Library/Application Support) from one computer to another? That’s definitely faster (at least in a local network) and prevents errors.
well, that’s because I’d always have to keep in mind which one of the data bases is the recent one. It ends up with "Oh shoot, I can’t add this entry because I don’t have the latest data base at hand. I first have to get the recent files from… what computer?" 
For me at least it is easier to exchange the recently added entries instead of the whole data base files. As some of my computers are not on the same local network I’d have to carry some amount of data with me (USB stick or something). Maybe I’ll try rsync sometime.
You probably have already thought of this, but it would be really
nice if DEVONThink had an iSync plug-in that would merge/sync
between two devonthink databases or between
devonthink and .mac/iDisk. For those of us with both
a laptop and a desktop system, we then wouldn’t have the
headache of having to mess around with copying objects
by hand between multiple computers.