Hi Link,
You can try www.myconversionbrain.com It does exactly that so that you can know which leads came from which keyword, adgroup, campaign. It also tracks which display partner or remarketing site generated the lead. Basically it tracks down all the source traffic (Google organic, Bing, Yahoo, Facebook, referring links etc) for all the leads that you get automatically.
Plus it helps managing your leads so you can see which keyword delivered the best ROI and which ones waste your money. So you can see the status of the lead from the initial stage of the closing. It also does other cool things like notifying you immediately once your leads come back to your website again and you will see which page the lead inquired on as well as which pages he has been to (before and after inquiry).
If you want a free free demo (10-15 min) let me know and I would be happy to show you using screenshare.
Cheers
Johan Hedin
