"Free" cloud storage offers can be gimmicky and require you to jump through a few too many hoops sometimes, but Microsoft's offering a pretty solid deal that doesn't call for much effort. Sign up for the company's Bing Rewards program, and you'll get 100GB of OneDrive cloud storage that's good for two whole years. If you've already registered, you're still eligible to take advantage of the offer. There doesn't seem to be much in the way of fine print or an obvious downside here — aside from getting spammed with the occasional email. Bing Rewards is Microsoft's program that doles out credits whenever you search with Bing or MSN. Collect enough, and those credits can be used towards gift cards, sweepstakes entries, or donated to charity.
But no one says you have to bother with any of that. You can sign up for Bing Rewards, never use it, and still enjoy the luxurious chunk of cloud storage Microsoft is handing out. The company says you'll receive emails and offers about Bing Rewards, so it might take some inbox management if you have no desire to hear about the service ever again. And if you happen to prefer Google Drive, it's worth noting that Mountain View is currently offering a permanent 2GB increase to your storage if you're willing to complete a quick security checkup. Reserving some space in the cloud for your documents, photos, and music is getting cheaper pretty much everywhere you look, but nothing beats free.
Update (19th February): Microsoft's free OneDrive storage offer now works worldwide using this link.