Currently, I have a bookmark to Gmail Mobile replacing Mail.app in the bottom row of my springboard. To me, Gmail Mobile is just so much better then Mail.app. I love the ability to view it in landscape mode, and it's tighter integration with other Google Mobile services, like Reader, Calendar (Yes, I use Google Calendar Mobile rather then Calendar.app), and Docs. The only downside I can see is its load times, associcated with it being a webapp. What do you guys think?