Google Trends was recently updated so that you can compare the relative search frequency of different keywords. There are some great examples here that show a lot of interesting insights and trends: Google Trends 2.0 - New Keyword Research Weapon? Discover My Killer Insights Check it out. What other keywords are of interest to you? Share some here so we can discuss.
Yep. I saw the featured thread over at SitePoint the other day. They haven't updated everything yet, but give them time. Some of their hard data is disappointing, while others are either intriguing to downright facinating. The rest merely confirmed my suspicions.