Genie Texter 0.81beta
http://www.genietexter.co.uk/
Basically a program which manages free SMS account on websites such as O2 and freeSMSmate to do the dirty work. It uses ure login details to access the sites and send ure mails. Also keeps count of how many text you have sent using each account.
I downloaded it this morning and am finding it cool . It can also check pop3 mail, and will notify you of any new mail via SMS.
Ive also just read that the guy who makes the program is planning to include "text compression" - basically something that translates 'text' to 'txt' etc.
Some of the services they have are not all that - UBOOT requires you to pay, and another gave you 5 free a day, but if you go over it'll automatically charge your phone!
My GenieTexter is currently on the way to manage 480 txt a month with 118 O2 and freeSMSmate.