I'd say that the credit card usage in restaurants depends on the type of restaurants you frequent. If you're talking higher end, and/or those catering to tourists, yes, you can use credit cards. But I'd venture to guess that some 90-95% of restaurants here do not accept them.

One note about the "radio taxi" thing - this comes up time and again. Hailing a radio taxi is no safer than hailing a non-radio taxi (I'm not talking about a "gypsy cab, i.e., one that isn't even licensed, just someone in a car offering you a ride - which if you accept, you're simply nuts...). The whole thing about radio taxis applies ONLY if you call the taxi company to request the cab - so that a dispatcher has your name, where you were picked up, where you were going, etc. It's a hold over from problems that really more occurred quite a few years ago, and isn't really an issue here anymore, but then, it never hurts to be extra safe. But again, simply hailing a cab that has a radio versus one that doesn't is a useless gesture.