Bec, don't rely on memory sticks. I bought a 16GB stick at the swap-meet a few weeks ago and one morning when I put it in I was asked for format it. I brushed this off as a coincidence, so I formatted and it work fine to another week before I got the same message. That $30 stick is now landfill.
Also, as someone mentioned here months ago: A portable drive is also fragile, and if you carry it around, say, with your laptop, then if you lose the bag you lose the lot. I'm not even sure how long CDs and DVDs are guaranteed to viable and readable these days. At least a decade I hope. Each month I run a selected backup to dual-layer DVD, verify it and put it in the toolshed. I'm hoping that cloud storage will simplify by manually implemented daily/monthly backup tasks. I've purchased a Rackspace 'Clound Files' account, which is just space in the cloud, which suits me fine. They have a primitive web interface to manipulate files. But as ManiacD said, it's just space so I have to work out how to best use it. Rackspace publish a REST API and a C# wrapper library and a demo WinForms app, so it looks quite easy for me to write my own simple sync facility, or even a fancy general-purpose GUI. I can't find any security statement by Rackspace. I'm not sure what their angle is on this issue. Greg