When a buddy in Baton Rouge recomended dropbox, I opened up with a suspicion-based defense of my not really that useful iDisc/Mobile.me online storage feature as being the same as, before politely thanking him for his interest and filing the info in “maybe later, sometime”. Times change, in this case a few months, and Bob’s your uncle, it works great for a whole bunch of stuff. Plus it’s infinitely better than Apple’s slower than a TSA patdown at a stripper’s convention alternative.
If you at any time need to backup critical data, synch client info, or work online from a remote location, dropbox is for you. Otherwise, just move along.
I could go on, but this Macworld review says it all, better, with examples. Dropbox Review | Macworld Wonder how long before they hook in a mail app to use with?