netflow export on catalysts

Hello Guys,

I have exported netflow, so far, only from cisco routers. But I know cisco switches (catalyst) are also capable of exporting netflow.

I would like you to help me with some primary questions on that.

1) are ALL cisco switches capable of exporting netflow, including the old ones ?
2) if not all switches are compatible with netflow, can you point me starting in which models i can have netflow ?
3) i know cisco switches have a command-line configuration system very similar to routers. Do they run IOS too ?? If yes, can the IOS be easily upgraded just like on the routers ?

Thanks for your help guys.