During our last online learning experience my favourite tool that we used was Google Docs. We were able to collaborate by working together on the document at the same time and communicating through a chat on the right hand side.
To get started, you will need a Google account. Once you have an account, you can create any kind of office documents as well as surveys and SMART files, or even upload your own.
Here is a sample of a group reading response that we did online: