How many address books do you have? Personally, just with Google accounts, I have three and they are also synchronized to my Android device. Almost every entry that I have is incomplete, consisting only of a name and an email address. Sometimes you need more than that.

There are great solutions such as Rapportive and Xobni for pulling in contextual information and Google’s newly-announced sidebar for Gmail will help as well. But for that other information, there hasn’t really been a solution until Rainmaker.

Rainmaker is a startup that’s presently working its way through the TechStars program in Boulder, but part of its product is already live via the Rainmaker website and Chrome app. The micro-scale idea is that it pulls in publicly-listed information for your Google contacts and then syncs them back in real time. The effects are pretty astounding, if you have someone with a hefty amount of public information, but even those with light information get relevant, up-to-date details added.

Need an example? I found a good one in Barry Schwartz from Search Engine Land. Here’s the before:

Screen shot 2011 05 27 at 4.52.02 PM 520x215 Rainmaker completes your contacts with a single mouse click [$30k API Contest]And then after I “Make it Rain”:

Screen shot 2011 05 27 at 4.52.32 PM 520x257 Rainmaker completes your contacts with a single mouse click [$30k API Contest]As you can see, it pulled in Barry’s website information, plus the public address for his business. The team is working hard right now to make Twitter results more reliable, but it generally does an admirable job of pulling those in, too.

I had a chance to talk today with Dan Lynn, the CTO of Rainmaker and what the company has going on is really impressive. First off, Lynn clarifies what Rainmaker is wanting to do on a more macro scale:

“We’re effectively building a people search engine. We’d love to be able to provide information like ‘hey, we found this information about you, and we found it in these places’. We want to do all of this in a white-hat sort of way.”

We talked for a bit on privacy, and this is something that Lynn says is vitally important to the Rainmaker team. By the team’s estimation, about 40% of people simply don’t know and don’t care about their information being on the Internet. Another 30% vehemently protect that information and the remaining 30% are the more social types who see the Internet as a personal branding opportunity and so they regulate the information that is available.

“We don’t want to market fear. We’d rather empower people to know where we found information and then have them be able to correct it or opt out of it completely.”

As for the money? Right now, you’re given 25 Raindrops for signing up and another 25 for verifying your email address. That should be a decent start for you to decide whether or not it’s worth the few cents per contact to have full information. Beyond that though, there is an API that is bringing in cash for the service. Non-commercial use of the Rainmaker API is free, and commercial use is only $.01 per match.

The team has put together a contest (details here) surrounding that API and there are over $30,000 in prizes available for it. The only rule? Build something cool. The first place winner will get $2,500 in cash, plus mentorship from TechStars, books from Brad Feld and David Cohen plus a huge list of other niceties.

I’m about as OCD as could be when it comes to keeping my contacts tidy. Rainmaker solves so many issues for me with a single button click that I’ll be using it for everyone in my most contacted list. As we push ourselves toward more transparent online identities, I think that it’s critically important to have information at hand. The beauty of Rainmaker is that a single click of the mouse can replace countless time spent digging for information.

Give it a shot. I’d love to hear your thoughts, even if you’re just telling me to stop being so anal-retentive.

Which won’t happen, by the way.