I have the HTC EVO 4G phone and thought I would input my use on the job as well. I use sprint as the service provider.
I was at an install where some one lost the instructions to a bathroom light sensor I had instructions in about 3 min with it up and working using Google search.
I use Barcode scanner and Shopper that is a photo product scanner to find specs on material I am not familiar with install howtos etc..
Weather channel
a Notes widget, Convert pad, RealCalc, and a Camera on one screen. This is my secondary job screen.
On another screen I have bookmarks to tool specs, manuals, this web site etc..
And on another screen I have a calender that is synced to my computer and also my wife has access to add appointments and set alarms from any internet connection.
Finally I have a misc screen of things I use some are repeats from other screens. One that comes in handy is Where Am I it gives me info on where I stand:
Phone Code
Zip Code
City Street
County
State
Sunset
Sunrise
a map
Elevation
and GPS Coordinates
also on the screen some of the things I use are a timer, quickoffice, and Simple notes.
When I add customer contacts it is synced with my email so when I sit down at the computer I can send PDF, Sketchup avi's and be done.
And one thing that I am going to try out is Google Googles to be able to scan in business card and input strait to contacts.
Thanks to this form for reminding me of this application.
Also tethering is big for me I use it on my laptop at customers home while I design in Sketchup in front of them great for download componets etc