I use Office365 extensively at home and on the go. OneNote in particular is a must-have for me, and it needs to be synced everywhere. Really wish it wasn't blocked at work. I have a Windows Phone so I can access everything over 3G, but working on a phone is nowhere near as comfortable as working on a laptop or even a tablet.
i pay a fiver a month (euros) with my mobile phone provider, gives me exchange email on all my devices, sharepoint for office and one note, one note online, and lync... its very useful and very reliable.