Meteor, like most Irish cell phone carriers, gives its customers 300 free text messages via their website (after login). However, for a quicker and easier way, with loads of potential, try emailing <number>@sms.mymeteor.ie. Within seconds, a text message with the sending email address and the contents of the message (cut off after 160 characters) will be delivered to the Meteor phone.
With some clever Gmail filtering, this could be used to send you a text message everytime you get a new email to your Gmail account and forward the first lines of the email. I’d be pretty stressed out by that, though.
A list of similar services for other carriers around the world is here.
And yes, it’s free. I mean, who would they charge? My Gmail account?