Making deals at the final table

[dowlinga]

I've heard and read about deals being made at both the final table of big events as well as between the last couple in Satellites for big events. Can anyone fill me in on how deals are made, what makes a fair or typicall deal, and finally what it means if someone asks you if you want to "save" one (ie. a buy-in or $500)? Just in case Im in the situation some time soon [img]/images/graemlins/wink.gif[/img].
Thanks
Ashley