I've owned a blackberry since they first came out. I've tried an iphone and all the other touch screen phones, but can't get used to the touchscreen.
I think having a smartphone is VERY NECESSARY. Now of course you'll have an argument with someone who doesn't own one, because they don't know what they're missing.
This is how my day starts....
* wake up - CHECK MY BLACKBERRY CALENDAR to see what i have for the day
* click the weatherapp ON MY BLACKBERRY to get an idea of the conditions
* check my emails ON MY BLACKBERRY (because I tell all of my clients to email me after 6pm because I have a wife and a son that get my time when I get home from work)
* while on the job, if a customer has some idea or wants a quote, I make a quick note of the conversation in BLACKBERRY NOTES
* if they want a tree replaced, I make add it as a task in BLACKBERRY TASK
* most of my clients are just as busy as I am and can't always make a phone call (meetings, etc) so they'll shoot me a quick email during the day. BLACKBERRY handles that well
* i do online invoicing with Wells Fargo and when I'm at the clients home who hasn't paid and "forgot, are you sure"....boom, just click on the Wells Fargo app on my BLACKBERRY and show him/her that "invoice 010 is marked unpaid".
I could go on and on