Each of the free or low cost online storage services for individuals and SMBs have their own strengths and weaknesses. Just when I think I have found the perfect compromise and am ready to settle down on one product, I find out more about what it can't do and also I find out more about what the other services can do!
I have an evolving list:
http://www.sugarsync.com/ backup and synchronization
http://www.dropbox.com/ backup and synchronization
http://www.mozy.com/ backup
http://www.live.com/ for MS Office docs and others
docs.google.com for Google docs and others
idisk.me.com for any docs
So, dropbox vs sugarsynch vs office live vs google docs vs idisk?
Am I missing your favorite tool or service?