This ‘suite’ approach is taken to its extreme by Apple’s MobileMe service. Apple’s intention is to get you to upload all your personal files and information into the cloud – and if you end up so reliant on the service that you keep paying £60 a year for them, all the better. It also provides all sorts of Apple-esque multimedia gimmickry, such as online videos and slideshows, and even a feature for locating lost iPhones.
Its iWork.com service is similar. It's free, but you have to buy Apple's iWork productivity suite for either Mac or iPad. Purely document centric, it's designed as a to make presentation, word and spreadsheet files that you have created available on one the move, or to other people for collaborative working. It's fine if you only work with those document types and those apps, but I'd prefer something more generic.
Review: Microsoft SkyDrive Live Mesh
Microsoft offers two online storage services, of which Live Mesh is the most versatile. You can download the Live Mesh software onto a Mac or PC, and then use it to upload and store up to 5GB of files online. It also allows you to create a folder that syncs your files across the cloud and multiple compiuter. You can sync your Internet Explorer favourites too.
The Live Mesh software is very straightforward and easy to use, although Microsoft manages to confuse matters by creating an odd overlap between Live Mesh and the more basic SkyDrive online storage option. The 5GB of storage provided by Live Mesh is actually just a chunk of the larger, 25GB of free storage that is available with SkyDrive – which you have to sign up for separately.
That seems unnecessarily complicated, but at least you’ve got 25GB of completely free storage available for back-ups, even if only a 5GB chunk of it can actually be synced via Live Mesh. Unlike Dropbox, it's never clear which files have synced and which have yet to be copied up or down the link.
Reg Rating 75%
Free Storage 25GB (SkyDrive) 5GB (Live Mesh)
Extra Storage N/A
More info Microsoft
Next page: Verdict
Do these 'free' services help themselves to a lifetime worldwide licence to use your data?
Can you be sure data you've deleted is gone?
Is my data encrypted?
What assurances do you have over availability of your data?
If the company goes bust does the liquidator inherit my data?
If the company goes bust can I still get my data?
Where do the back ups go?
Is it legal for my data?
Before you upload your office data to those services have you considered the impact on your companies policies and legal requirements?
Are you transferring personal data out of the EEA and therefore breaking the DPA?
There are so many questions you have to know the answers to before you use these services. It's not simply a matter of how much is it and how easily can I spread my data.
from a home user's perspective...
Will amazon/apple/microsoft/et al be trawling through my files to try and sell me things?
Will I find my university thesis/latest novel in progress/etc available via Amazon if i search?
Will i find my holiday photo's used in Microsoft's latest marketing campaign?
whilst other people getting at your data is one thing, how trustworthy are the people you are handing it to, and what access are you granting them in exchange for this "free" storage?
I agree, there is a lot of questions that *everyone* should be asking of on-line providers, and I guess the above list covers the key ones. In fact, the simplest of all is this:
Do I have the encryption key, and it is not known to the storage host?
For most other factors, where the data is held, what happens if they are bought/liquidated, etc, they become less important as they cannot DO anything with my data as they don't get it plain-text.
OK, you have to ask what happens if it vanishes, but again you must look at the 'cloud' as a good HDD, not as a complete solution. You should have 2 copies of your data no matter what! 
And I know the arguments about de-dupe, but surely you could have a user-side client encryption that is block de-dupe friendly by encrypting blocks of the same size (4kB, 64kB?) with the same key-based pattern so they still de-dupe even if the plain text is unknown?