Are iPhone sim cards locked specifically to the iPhone hardware? I've got an iPhone 3GS, on the UK network of O2

Can I take that sim card out, and put it into another mobile device (not iPhone) ? I don't have a spare device to try this hence asking here

More importantly, would the sim card actually work in a non-iPhone device or is it locked for iPhone usage only?

Thanks
No SIM card is locked to any phone. The SIM card will work in any unlocked device supporting the frequencies used by the carrier that issued the SIM card.