Late last week Apple made a change to their iCloud web services, opening up the iWork for iCloud beta to everyone. Previously the iWork suite of web apps (Pages, Numbers & Keynote) was limited to those users who owned an Apple device.
With last week's change anyone can go to beta.icloud.com, click the banner (shown above) to sign up for an Apple ID (which includes 1GB storage) and use the iWork for iCloud beta. Just make sure you do head to the beta iCloud website, as the main iCloud website doesn't let you sign up for an Apple ID yet. The iWork for iCloud web apps, which are still classified by Apple as betas, was first announced at WWDC 2013.