If there is one advice I can give you in 2012 it will probably be to backup your data more often and reliably. I've been doing regular backup of important data such as documents, pictures, videos and music for many years. Unfortunately I had to learn it the hard way, I relied too much on my computer's hard drive, until one day it started click and was deemed dead. I had gigs of music, holiday photos and assignments that I had luckily submitted just a few days before.
There are many backup software around. I personally use Crashplan to backup large quantities of data (thanks to its unlimited plan), Duplicati to backup only the most important of things to my offsite server and Wuala to backup what Duplicati backs up plus provide me with sync capabilities. The one that is most active on my devices is Wuala, since it offers more features compared to the others.
Wuala is backed by the French storage company LaCie and until recently one of its features was its P2P design (they removed that but please read on!). They offer 2GB for free (just like Dropbox). You can manage your stuff through the desktop software (Java therefore cross platform) or through a Java applet. You can also share your files with others either through the software (adding them as a contact) or any web browser (no need for Java here). You can control various privacy parameters. It can sync folders between your various devices. Oh and backups on a schedule. Last but not least, they have an iOS and Android application that, for now, allows you to only access your files.
Most of the features seem similar to the rest. But here is how Wuala is, in my opinion, superior and better than the rest. Firstly all data is encrypted on YOUR computer before being stored on Wuala's servers. Unless you share your password, your data is safe. Secondly, your data is stored in European servers (France, Germany and Switzerland) which have stricter data protection laws than the US (where many of the other backup software store data). Then there is the sharing issue where a unique key gets generated to access the files online, and since it is done on your computer you shouldn't be affected by what happened to Dropbox. They are also much cheaper than Dropbox for additional storage ($119.88/year Dropbox vs. $79/year Wuala for 50GB additional).
Wuala also supports keeping revisions or copies of files you have modified or deleted in case you need to revert back (although it is stored in the "Trash" folder). It also supports incremental (upload modified pieces of files rather than whole file again) backup, although it must be enabled through a switch or edit of the config file.
There you go, I have provided links to several backup tools (Crashplan, Duplicati and Dropbox) and provided a detailed review of the one I like the most (Wuala). No more excuses not to backup more often this year!