Install the free application Dropbox on all of the computer devices you own. It will increase your collaboration productivity. This will eliminate the need for you to create a large email trail of annoying document revisions. Also, instead of having to ask whether the most current revision of a file is available, everyone will automatically have the latest files. You can share with anyone or any device if they have a Dropbox application.

This is how it works.

 

1. Install it first on your laptop/desktop. By going to www.dropbox.com
2. Do the typical install and it will place a folder on your computer called “Drop Box”
3. Any file you put in your dropbox folder is placed out on the cloud and can be shared with anyone who has Dropbox. Files will be only visible to your account until you give others permission to access parts, or your entire Dropbox folder.
4.  Install the app from iTunes, or the Android Marketplace. Sign in with your account credentials.
5. When you open a file in your Dropbox folder and save it, that revision will be instantly available to everyone you shared it with.

This solution will not allow you to simultaneously edit documents with another person, but if two people do edit at the same time there will be duplicate files saved. I suggest renaming the file as “checked out” so coworkers know you are actively editing.
Apple currently uses iCloud to push purchases in your iTunes account to all our devices wirelessly. This does the same thing, but is open across more devices(Apple and Android). This should be rather obvious, but you must have a wireless internet connection for the documents to be updated. You also need to install the appropriate software on your devices to be able to view certain file formats.
For Apple, there are a number of third party applications to help you view and edit your documents on mobile devices:
Numbers(Excel), Keynote(PowerPoint), Pages(Word)