I've had very mixed results with this topic. I can see that the concept of taking emails to the document, rather than attaching the document to multiple emails is a great concept. At work we manage this for shared documents by putting them on a common drive and all doing our commenting and editing there. But it would be very useful for moving things between work and home and vice versa and for material that needs looking at by people who are all in sorts of different places.
Ever obedient to my instructions ;>), I first went to explore Zoho and was excited by the prospect of a site where I could write, use a spreadsheet, notebook, database, planners, create a wiki, do mail etc. But that's where my excitement stopped. I tried to sign up and crashed Firefox three times attempting this. At that point I gave up and moved on to #19 which explores the Web 2.0 awards. I was interested there to note that in the Organize category they gave Google the first prize and Zoho the second. Why not try the best as the second-best didn't want me?
Using Google was completely simple from a sign in point of view as I, of course, have a Google account and it just welcomed me and identified me. Google documents allows one to create or upload documents, spreadsheets and presentations, others can be invited to join in either to read or write, and publishing is possible to your blog or to a url. I was particularly interested in uploading, so I uploaded a word document from my desktop. That seemed to work very well and to keep all the formatting. Then I successfully uploaded the document to my blog, and also to a website. These both seemed to work very well. I have since deleted that post as a long document on Foy & Gibson was not likely to be of interest to most who would be reading this blog ;>). I'll do some shorter ones when I finish this post. Experimenting with the presentation part was more problematic. I tried uploading several Powerpoint presentations from my desktop and none of them seemed to work very well.
So, my reflections on this topic are that it is a great concept and could be very useful. However, it does not seem to be working perfectly for me at this point, and maybe Google documents need developing more. It might work better with documents created internally as almost inevitably something is going to happen to formatting etc if you are transferring them. Zoho, I can't comment on except to say @#$%.