I think the reason, or one of the reasons, I like Dropbox so much is that it makes my various computers and my phone feel more like one platform focused on me, rather than several different machines with different files and different software, disconnected across various sites and separated by firewalls. One thing I particularly like to do with Dropbox is manage my podcast playlist. I download podcasts on my desktop - any one - into Dropbox, then use the Dropbox app on my phone to copy them there. When I delete them from Dropbox on my phone, they're gone from my desktops as well. Very handy. I use it in a similar way to manage my free ebooks that I read on my phone too. Killing time is the killer app on my phone, but using Dropbox makes the process much easier, and even fun.
Mokalus of Borg
PS - I don't know how I'd do without Dropbox now.
PPS - Possibly with some arrangement of a flash drive and sync software.