Writely and Numsum, web based word processor and spreadsheet

This is Thanksgiving in the US.  I had family over.  And I have some great clients and some of my family asked if "we had an Apple Pie like the one we had last year".  The answer is no.  Technically I replied with a story, and the story goes like this. 

A client of ours used Excel to create a spreadsheet to manage their holiday gift lists.  You know the type, who gets a card, who gets a pie, who gets coal and who is on the short list to turn over to the ninja hit squad.  I am honestly not sure where we were on the list last year, but we received a wonderful applie pie. 

We did NOT receive a pie this year, and based on a conversation last spring I think I know why.  They created a spreadsheet of who gets the pies.  Hid the rows for everyone who does NOT get a pie and emailed a spreadsheet from Excel that showed 50 or so names.  The company that received it uses an old PC with Microsoft Words.  MS Works does not apparently support hidden rows so they sent pies to 300 odd people, basically EVERYONE on the list.

In the spirit of "prevent that problem from happening" I recommend two more must check out products for social collaboration.

1) Writely – web based word processing using just a browser with collaboration functionality.

2) Numsum – web based spreadsheet application.

Check them out.  Both writely and numsum are potentially significant threats to Microsoft even with the new release of Office coming out.