Here is a brief overview of the web sharing/syncing solutions I am actually using. Although I hold a Mac account with an iDisk allowing to store remotely my synced files, I found it somewhat slow (especially during upload). Moreover, it does not offer support for cloud computing with live documents, like e.g. Box.net. But this one is very expensive if you want to get decent capabilities (check for yourself on their website).
Now, what about other options?
Most of them are available on iPhone too.
I discovered Dropbox at the beginning of 2009, and used it a lot since then. The latest beta version (available on the experimental forum build) offers several improvements, including selective syncing and getting a shareable link for any of your folder (and not only the
Public folder). I am waiting for the release of Elements which promises another great enhancement to Dropbox.
I also discovered Dropzone which is an application/script launcher sitting in the Dock. It offers useful shortcuts like URL shortening through bit.ly, upload to your Flickr account, sharing snippets (gist) on Github, etc.