hi! i am an expert in SMPP (Protocol to exchange data between sms-centers) I've developed some sms-shops, chats and other services. "7-Cheap cost per sms, not more then $0.035, less is better as out market price is less then $0.02" - it's fully depend on your cell operator, who's sms-center you will use. For example, BeeLine Russia - takes 0.04$ for each outgoing message, and 500$ monthly for SMPP account - it also let you to set up an incoming message price, i.e. - you have shot number 123 - you perfom service like "check email" - client send you an sms with string "check email" - you check his email and sending back answer "3 new, 12 total messages in your box". You can set up price for incoming messages - for example 0.20$ - - i.e. cell-operator will write off 0.20$ from requester and transfer it to you. Etc. Let discuss details using PM or (preferrably) ICQ or Yahoo IM. Project that complaints to your requirements - isn't cheap project. it would cost around 3000$. Contact me if you are interested. Goodluck anyway!