I have been exploring this tool a bit further. Previously I tried uploading a word document, and then publishing it on my blog. This worked well and seemed not to lose formatting. I have just played around with creating a presentation. The software is very clunky and I also discovered that you can't upload the presentation document to a blog. I also experimented with uploading a biggish excel file on Collingwood Hotels. This seemed to work fine. Again, the Google spreadsheet does not have an option for loading to blog.
Continuing to play around with this has been of use to me in terms of discovering a practical and immediate use for this. I am working with a team of people from the Collingwoood Historical Society to update material about Collingwood hotels. I have the master excel spreadsheet of information on my desktop. Now I have it also on Google documents and will be able to invite the others to add their comments there directly. I notice there is also a chat facility. So my next step will be to invite the other team members to make their additions to the spreadsheet on Google documents. I am not sure how that will display, ie will we know who has made what changes? I presume that won't be like track changes, but will appear in the list of versions which seems to track even the most minute change. The first trick will be to make sure that the people I invite to share don't dismiss my invitation for spam. This happened recently with a new blog I set up! They just don't know me as Polyxena.