I have an iPhone, and have had one for about 4 years. I originally had a 3G with AT&T "service" tagging along, and now I have the 4S with Verizon "service." Yes, both have crappy service. Both drop calls more often than a skittish wide receiver going over the middle - at least in my area. Both had such bad service at my house, I had to get a micro cell tower for both in order to even get and receive calls.

It's a good thing I use it far less for synchronous vocal communications (read: phone call) than asynchronous information exchange (read: texting and/or data access). The intermittent nature of the service is of far less importance for data than voice. And, for me, it's the data over the voice communication that makes owning a smartphone worthwhile.

Speaking of voice (ha, get it?), I gave Siri a whirl when I first got the 4S a couple of months ago. It was interesting - when their servers weren't overwhelmed, disallowing any information return. Now, it appears Siri has some competition. Evi, created by True Knowledge, a Cambridge, U.K.-based semantic technology startup can answer questions posed by voice (using Nuance software) in a conversational manner or by typing. (Nuance is the current incarnation of Dragon Naturally Speaking voice recognition software.  I gave it a whirl back in the late 1990's as an addon tool for my legislative drafting software that I wrote. Unfortunately, it never worked quite as well as I hoped back then.) 

Evi is intended for use as a general reference for facts and location-based information (think Yelp or AroundMe). I read that some users have issues with Evi servers being overwhelmed as well. I haven't yet given Evi a try, but being on the west coast of North America, and True Knowledge being in the UK, I anticipate the 8-hour time zone difference alleviating the server load issue for me.

For computational information, I use the WolframAlpha application on my iPad. It's now a mere $9.99 and (for me) exceeds any mathematical needs. I don't know if it matches the overall power and elegance of Mathematica, but for 1/100 the price of the standalone application ten years ago, that's OK. 

A favorite query is to input two given names and get a comparative analysis of those two names' use over time. You can do this on the web as well, as they both link to the same servers. I also used it to review my son's homework. He has a graphing calculator, I have Wolfram Alpha.

 I think I'll give Evi a go as another handy tool for the computer in my pocket.

I finally bit the bullet in a couple of ways this week and updated my old phone and changed carriers simultaneously. We had been using AT&T for the last forever years, but the signal strength at the house was not bad - it was abysmal. Typically, it would be one bar, dropping to no signal after a minute or so into the call. After numerous complaints using their handy iPhone app, AT&T sent us a microcell tower that hooked up to the DSL line. Whoo-hoo! Five stinkin' bars! As long as you stood in the kitchen where the tower was. In my office 50 feet away, or in the kids' rooms also 50 feet away, the signal strength dropped to one to two bars. Not as bad as with no tower, but still, pretty lame.
Enter the new iPhone4s and Verizon.
Signal strength at the house is a solid 2-3 bars. Considering what it was before, that kind of performance can only be described as relatively stellar!
The screen on the 4s is so much clearer than my old one, and the ability to use iMessage in addition to text is nice. I also am impressed with the way I can do a voice text. The recognition is pretty good. I can even do smilies that way. I need to find out about if I can have the phone read incoming texts, though.While driving, that would be a really nice thing, especially as Nevada has a law now banning hand-held cell phone use.
The kids really enjoy asking Siri ridiculous questions like "where to dump the body?" and "what are you wearing?" I did ask it what the answer to life, the universe and everything was. Already knowing the answer to be 42, I was gratified to see Siri also knew. :-)
Other considerable improvements over my old phone that are immediately noticeable are the speed and battery life. I used to wait seemingly interminably for things to happen on the old phone. I guess what was considered speedy in 2008 is pokey today. Either that, or my old phone simply got tired in its old age. I know the button's sensitivity was about shot; I had to mash it before it would recognize the action. No longer. With the new Blue Jet, all is happy clappy. And fast.