SpyFu

Are you thinking about doing a Pay-Per-Click campaign and want to get an estimate on what other people are bidding for key terms? Or, do you want to see who the top bidders are in both the PPC results as well as the organic results? With SpyFu, you can view the rough cost per click estimate, as well as see related terms purchased by those who purchased the original keyword for which you searched. They also offer an annual, monthly, or 3-day paid subscription to access more in-depth information. The only downside is that the info presented is about 2 months old, so YMMV..:)

Check out your PPC terms here.