i think properly tracking all your conversions down to the keyword level is the most important thing you can do in ppc.
for example, if your campaign has 5 keywords, and only one of them is turning a profit, but you're only tracking conversions on the campaign level, then the only thing you'll see is that the campaign as a whole is unprofitable, and you'll be forced to scrap the whole thing. if you tracked conversions on the keyword level, then you would have been able to only stop the 4 unprofitable keywords while keeping the one that was making you money.
anyway, i highly recommend prosper202 for keyword-level tracking. i actually just recently started using it after half-assing my ppc tracking for 10 whole months LOL. it's making a huge difference. it actually lets you see the exact search phrases your visitors are using to reach your site. and if you're using content network ads, you can do a reverse referer lookup to see the exact page your ad appeared on. powerful shit.