I am thinking of buying a new phone, Vodafone 541 Black. But, I may need to change the sim from vodafone to o2....by the way, the make/model is vodafone, like nokia and samsung etc.

Is it possible to change to o2 from a vodafone model/make.

Also this phone is touch screen, how do you text?
Does anyone know if this phone is good, and do you recommend any easy to use and cheap phones? But also nice.

Thanks

This is the phone I want
http://shop.vodafone.co.uk/shop/mobile-phone/vodafone-541-black?phoneView=ImageGallery