Here are the email addresses for the most popular cellular phone carriers:
Verizon; phone-number@vtext.com
T-Mobile; phone-number@tmomail.net
Cingular; phone-number@cingularme.com
Sprint; phone-number@messaging.sprintpcs.com
Nextel; phone-number@messaging.nextel.com
Virgin Mobile; phone-number@vmobl.com
ex) email to [email protected] with text "Hello ipBalance.com"
Free for sender, but regular text message charge for receiver.