Email SMS Text Messages (Free SMS)

Inspired from the Sprint Treo SMS post, I have decided to post email extensions to U.S. wireless providers. This is handy if you have a smartphone with email or you can use your PC to send a email text message without being charged (the receipient will be charged for receiving). Simply input the receipient's 10-digit phone number infront of their carrier's email extention and they will receive your short email via SMS. Several downsides to this method: 1). Sender information will be some random number, so the recipient may not read your SMS. 2). Not sure if reply to that random number will work. 3). You'll always need to remember each carrier's email extension and know recipient's carrier.

T-Mobile: phonenumber@tmomail.net
Virgin Mobile: phonenumber@vmobl.com
AT&T: phonenumber@txt.att.net
Sprint: phonenumber@messaging.sprintpcs.com
Verizon: phonenumber@vtext.com
Nextel: phonenumber@messaging.nextel.com
Source
Source 2
Update 2/24/2008: For the hardcore SMS folks using a Nokia Smartphone, a Widget is available for you to blast SMS text messages via your phone plan but using your Windows Vista computer!