I don't know which cell phone service to use. I am currently with verizon and I

Verizon Wireless is by far the best! Why would you want to switch. Verizon Wireless provides the largest voice AND data network in America. They have 3G coverage nearly ever where they have normal service! They are constantly expanding and they are also the first responders for natural disasters. Verizon Wireless stands for something amazing.
Seriously, you will not find a better carrier. Verizon Wireless receives the awards from JD Power nearly every year.

AT&T doesn't provide good national coverage and they just got 3G broadband data. View the 3G map comparison: Dark Blue=AT&T and Light Blue/Green=Verizon
http://img525.imageshack.us/img525/2482/attvsvzw3gdt0.gif

Sprint PCS has poor customer service. T-Mobile is powered by AT&T where roaming exists. T-Mobile also hasn't even launched a 3G network. They do have excellent customer service though.

go to http://jdpower.com/telecom and scroll down to the section at the bottom.

http://www.mountainwireless.com/ratings.shtml

Verizon Wireless now owns Alltel, the fifth largest wireless carrier in the US. This will give Verizon an national coverage area 10 times better than any competitors. Verizon and Alltel have always been roaming partners, now Verizon owns them (or will in the near future). They will also have 80 Million customers.
http://news.vzw.com/news/2008/06/pr2008-06-05.html
http://www.alltel.com/wps/portal/AlltelPublic/!ut/p/c1/04_SB8K8xLLM9MSSzPy8xBz9CP0os3hnP2-DoCBDAwN_HxcnAyNLZ0PLIE9DIN9MPxykA0mFu3eokYFRgFOwWZi7i5GBgQFE3gAHcDTQ9_PIz03Vj9SPMsdpj7uJfmROanpicqV-QXZ2mnO6oiIAUfiTyw!!/dl2/d1/L0lJSklna21BL0lKakFBTXlBQkVSQ0pBISEvWUZOQTFOSTUwLTVGd0EhIS83X0NOSzBSUjEwME9MREIwMjlDMTlSSTExMEc0L09fX19fMw!!/?WCM_PORTLET=PC_7_CNK0RR100OLDB029C19RI110G4_WCM&WCM_GLOBAL_CONTEXT=/wps/wcm/connect/Personal/home/p/customerservice/annoucements/announcements_merger.html

Hope you reconsider.

Well, that I know of At&t has the best reception. That's what i have, and my phone works a lot of places. They also have the iPhone, if you are into that at all. There are also some cool slider phones. Hope this helped!