MyWi 5.0 is the best app for creating hotspits, you can even use your phone like an usb wifi adapter
Sent from my white, jailbroken iPhone 4 16 GB using iPF.net
When you add new contact or edit an existing one you should specify that he/she uses an iDevice (iphone) by entering phone number in a proper field.
Otherwise your messages will be sent as SMS until the person replies you and
then you'll continue to use iMessages.