I have also been lamenting the same problems coming from Windows Mobile as I am a heavy business user. Luckily I have been using a couple of solutions until Dataviz releases Documents To Go for the iPhone.
The first one, as a previous poster said, is a program called Files. It allows me to transfer any files I need to my phone via WiFi. Unfortunately, you can only view but not edit, nor email from your phone.
So the second solution I use is Log Me In for the iPhone. This allows me to access my laptop wirelessly from my iPhone, or any other computer, and work with (view, edit, email) the files right from my iPhone.
However, as a long-time Docs To Go user, I can't wait for them to release it for the iPhone.
Hope this helps.