My biggest nightmare is waking up one day and finding out that all my research data along with the analysis and completed chapters have all been wiped out due to a virus or something. This has actually happened to some unfortunate researchers and I am not taking any chances.
All my work is stored on my portable hard drive which is backed up locally on my pc (manually), and automatically online on IDrive. I am using the basic free version but I am quite happy with their service.
Dropbox review here. I have been using Dropbox for slightly more than 2 months now and I am really happy with their service. I can access and even edit my files anywhere - with access to the net. The upload speed is really fast as well - definitely way faster than IDrive.
Initially, I only got 2GB space as compared to 12GB on IDrive but I found out that I can increase the storage space up to 8GB by inviting others to sign up. If you register with Dropbox by clicking the link here, both of us will get an extra 250MB space. A great win-win situation. So far, only two guys have signed up via my link and now I have 2.5GB of space. Looking forward to getting more guys to sign up and get the maximum storage limit.