To me cloud computing means putting my data on the clod and being able to access it anywhere. But Yahoo!/Delicious kind of taking the magic out of it, as you need to worry about if your data is still going to be available sometimes down the road. There is no promise that Flick will not be gone. So does Facebook or even one day Google. End user still need to manage the data somehow, for example doing export of bookmarks from Delicious to another host. It seems that there really is no difference putting data in the cloud than putting on your local computer, except for the accessibility. Let say down the road when there is little internet latency and everyone's running 1Gbps fiber, and if I store my iPhoto library inside a Dropbox/iDisk/Box.net/WebDav folder, can this be considered cloud computing?
Not really. Cloud services have much greater reliability than your PC-- if you were to store your data on your computer with that 1Gbps connection, that doesn't save it from a hard drive failure.<p>Services like Amazon's S3 have the advantage of redundancy.
Clouds are meant more for storage. The serial computational power of the cloud can allow for highly complex simulations which would take alot longer on PCs and HPCs.