The importance of backing up your data - securely and offsite - should hardly need to be stressed to anyone reading this blog. There are many different services that offer secure offsite backup...my own personal favourite is CrashPlan.
CrashPlan offers probably the same features as several others: 448-bit file encryption, unlimited online backup, simultaneous backup between their offline service and your local devices so that you can keep a quick-access local copy of your data as well as that stored on their servers, etc etc. For $5 a month this peace of mind is easily worth it.
But here's the really cool part - because CrashPlan can be accessed via a web browser and their mobile apps as well as the desktop app, it means that all my data is available to me wherever I go. I have CrashPlan set to back up to the cloud every hour, so it's pretty much always all there. Of course I'll still use Dropbox and iCloud for files I know I'm going to be frequently editing in different locations - but should I suddenly need access to a file on my home Mac when I'm out and about, I can get it immediately via CrashPlan. Short of trusting all my data to Dropbox (and paying way more than $5 a month for the privilege), I couldn't otherwise do this.
I'm always looking to streamline the number of processes and apps that make up my workflows. So here's one app that collapses two functions - secure backup and cloud data access.