I’ve been participating in the DropBox beta now for a few days and whilst there any many similar competing services out there, the DropBox guys have really been able to distinguish themselves through their seamless OS integration.
Competing services such as Omnibox, Moxy etc. offer similar OS clients, but DropBox is the first that seems to match Apple’s own .Mac iDisk in terms of seamlessness: Your DropBox appears in the Finder and 
adding a file is as simple as drag and drop. A utility that runs in the background then uploads that to your DropBox account.
I’d even go a step further and say that it actually seems to work better than the iDisk. Adding files to your iDisk is a sluggish process that usually ends in a two second progress bar claiming your 200MB file has been uploaded in record speed, followed by 2 hours waiting for .Mac to “finish” the file.
The DropBox folder looks and feels like a regular local folder. The default behaviour is even “move” rather than “copy” when you drag items into it, which is a bit disconcerting at first. (Tip: Use option drag!)
Once you’ve dragged in a file, DropBox takes care of the rest silently in the background. Files are instantly visible online at your Dropbox account, even whilst they’re still being uploaded.
I’ll have a some more impressions later this week, but initially it does beg the question:
Why on earth doesn’t .Mac work this well? Apple already has OS integration baked in, so there’s almost no excuse for the current state of the .mac iDisk. For me at least, snappy, pretty DropBox – even in its current beta state – beats the pants off the iDisk in every respect.
Let’s hope the “.mac overhaul” the rumor-mill has promised for WWDC pans out.