Documents to Go is great.
Here's a tip for keeping all your MS Office docs and edits in sync on desktop and on your Android phone...
Buy the full Docs to Go app. From Android Market, download the SugarSync app. Sign up for the free 2gb account. Download the SugarSync desktop app. Install and set up the program to sync with the folder where you save.all your Office docs on your PC/Mac.
Now, any edits to your docs you make in either place will auto sync up to the SS cloud, and then. Will be reflected in the other place whe you open the SugarSync app.