Some Internet Service Providers (ISP's) in Yuma.

BroadBand ISP's

Q-West DSL
Call 928-344-9106 or 928-446-2764 (wireless).

Time Warner Cable
Phone 1-888-683-1000

Beam Speed
Fairly expensive, but available in Yuma Area

TeleSpectra
Phone 928-782-3636 or 1-900-749-7678

VoIP

With BroadBand service, you can also get VoIP (Voice over Internet Protocol). 
Here is some info and more here.
Some VoIP service providers:
Skype is great for free video calling from computer to computer and also a cheap phone service..
Net2Phone , Lingo , Vonage, Go2Call , DialPad, iConnectHear and Skype

Lots of people are already using some form of VoIP, either software based like Skype and Net2Phone or hardware based like Lingo and Vonage

DialUp Services

Three good ISP's in Yuma

1. Toast is definitely "The People's Choice" for the top ISP in the market today. Service with Toast will run you only $9.95 a month... and it includes a FREE Web Accelator to help you browse up to 6 times faster than regular dial-up service. Pay for your service annually, your cost will be reduced to just $7.95 a month!

2. Copper.net service runs just $9.95 a month. Their sudo high speed service is an addtional $5 a month

3. NetZero internet service starts at just $9.95 a month. Their sudo high speed service is $14.95 a month.

I found ISP.com to be an old reliable outfit at a low cost of $9.95/mo.
http://isp.com/