Anyone can run a “cloud” service – really. People have been running “cloud” services for a long time, before marketing got hold of the term.
If I want to be pedantic about it – when I remotely access the media stored on my home server you could say I’m accessing a content from the “cloud”.
So let’s be a bit more picky about what we call a “cloud” service. Have a read of my latest rant piece on BoxFreeIT: http://www.boxfreeit.com.au/Blog/make-sure-your-cloud-isnt-run-from-a-garage.html
If you want a great listing of attributes that cloud services should aspire to, have a look at Andy Milroy’s blog post (it’s a good one for “cloud” provides to benchmark themselves against): 16 Key Attributes of Cloud Computing