I personally think it is more than acceptable to go one or two steps further than this and ask the agent if you can come over and buy them a sandwich at lunchtime to talk over your CV and any suitable roles they may have on their books in more detail.
Anything you do to put yourself in front of the pack is likely to pay very big dividends. Let's face it, its not hard when the most effort the majority of people do is to fire off standard, untailored CV's to anyone with an email address!