Is it illegal to switch SIM cards between phones without advising the wireless phone company?

I have friends that do this all the time. I was just wondering if that was illegal or if they have to pay a fine every time they do it. Does the SIM card track your records and send it to the wireless phone company? It seems wierd!?
Categories: Phone Cards Tags: advising, between, cards, company, illegal, phone, Phones, switch, wireless, without
What is the difference between “Local” and “Branded” phone memory cards?

Hi Guys n Girls!
I have Sony Erricsson’s W200i. I wanna expand its memory. Please tell me is there any loss in inserting any local memory card of 2GB ?If yes then do I have to use the same card which is inserted in ma phone? Tell me the price also.
Categories: Phone Cards Tags: between, Branded, cards, difference, local, Memory, phone
Is there a difference between memory cards for a cell phone and a camera?

I want to put music on my new cell phone, but I need to either purchase software or use a memory card, would the same memory card for a digital camera work in this situation or do I need a special phone memory card? They seem like they’re almost alike, any ideas?
Categories: Phone Cards Tags: between, camera, cards, cell, difference, Memory, phone, there