Hiya,

Few years ago I used to use free SMS sending services from the net.
Havn't used on for ages, but as a point of reference, I used SMSpup.

Just took my phone off a plan, onto pre-paid, and now I've clean forgotten to buy credit.
A quick Google lead me to Intazaar which is doing a fantastic job for me.

They have lots if info when you sign up, and when asked about your location, you can nail it right down to suburb.
All messages sent to phones have the reply number set to yours, so it looks like it came right from your phone, and replying is easy to the receiver.

The layout, design and colour scheme of the website is one of the nicest I've seen, but all of the pre-drawn images are a let down to the polish of the generated images.

All in all I rate it pretty high at this point, though I've only sent a couple of messages.
Spam to the phone is guaranteed not to arrive so long as you agree to the terms and uncheck the promotions option whilst registering.
Messages only take a few moments to arrive, which made signing up easy as I didn't have to wait for their confirmation code.

They've taken the user profile to another level, as you can set you personal image, and they have journal features, though I'm not one to make use of them.

http://www.intazaar.com.au/

Sounds alright, whats the deal with contact lists?
and spamming more than one phone at a time?

just that other services used to require having no more than 10 contacts in the list at a time.
and mass SMSing is handy when trying to get an event together.. think LAN reminders !!!

They don't' support mass mailing, which you can kinda expect, and there is no requirement for having x amount in your contacts list.