What I have done is uploaded many of my word and excel files that I will need to make changes to on google docs, then I use an app called Gdocs by Wildart that allows you to make changes to the document. It works well for word docs but excel can be a problem. I have not used any of the paid apps ( Docs 2 Go, etc ) so they may work much better but this way is free and suits my need.
It's an investment and it's a little tedious, but I've been using Docs 2 Go since Palm days and it's even better now, with being able to view/edit Google Docs, too. If you're ok wit plunking down $15 for it, it will pay itself off.