Few tools had been in my radar for a long time before beginning to use them recently. First one is DropBox. Synchronizing the desktop, laptop(s), iPad and smart phones is a laborious task. Sharing data between them using flash drive and email attachments is not really a sophisticated approach. Enter dropbox, that provides 2 GB of personal storage space on the cloud. You can install a dropbox client in your devices and simply drag and drop the files into the dropbox folder.
If you want to access a PDF document that you downloaded in your notebook from your iPad, drop the document into dropbox. The same PDF can be accessed from the dropbox present in your iPad. Dropbox also generates public URLs for the files present in it. So you want to share a resource to others, no need for attachments anymore.
DropBox can be effectively used to back up your work as well. You can create SVN repositories inside your dropbox and work with the project from your Mac or PC or any other machine. The project is now safe and available on the cloud and can be accessed anytime from any device through an SVN client. Extremely effective for backing up your work.