I'v recently bought a mobile phone contract with free unlimited internet. my question is if i put the sim card into a usb modem and into my laptop, will i be able to conect to the internet via my laptop?Connecting to internet on laptop via mobile phone sim card?
No, it won't work. You can however use the phone as a "tethered modem" which means that the computer sees the phone as a dial-up style modem. Many Nokias and particularly BlackBerrys are good for this.
The problem is that most companies who offer unlimited internet will only allow it when using a particular browser on the phone, one that has limitations as to what sort of web site can be displayed, and they definitely won't allow things like streaming video, IM or youtube etc., without extra charges - often quite steep extra charges.
Check the fine print on the phone company's contract very carefully.