ReadWriteWeb

Several years ago, I spoke on a panel at an advertising industry conference with Om Malik and Michael Arrington. Arrington, my former employer, was bored by the conversation and mocked me throughout it. One of the last questions we were asked on the panel was what technology we were most excited about at the time. I said I was most excited by trends represented by a little startup called Rapportive, which sits in your Gmail sidebar and shows you aggregated information about whoever you are emailing.

Arrington laughed at me, just like he had laughed at me in the conference green room when I showed people photos on my phone of the chickens I was raising in my backyard. Just as I was vindicated when the TV show Portlandia later demonstrated that it is perfectly reasonable to raise chickens here in my home town, so too do I feel a little vindicated by the reported acquisition in the works of Rapportive by social network LinkedIn. OK, so both are a little silly. But the point is: Rapportive is awesome and I was right.

AllThingsD's Liz Gannes has sources telling her that Rapportive, the best thing that ever happened to email, has been acquired by LinkedIn. We've heard the scuttlebutt, too. Our friends at LinkedIn won't say a word. Rapportive co-founder Martin Kleppmann "can't comment," and CEO Rahul Vohra has been quiet on Twitter lately. That's all we know.

So we aren't reporting that it has happened, but we're bracing ourselves in case it does. Since Rapportive is the most useful plug-in ever, we're concerned about something bad happening to it. But if it had to be somebody, an acquisition by LinkedIn could be a good choice.

Can sentiment analysis be as simple as installing a browser plug-in and scrolling down a screen? You bet, and you might want to check out the latest from ViralHeat. In a matter of minutes, you too can be getting in touch with your feelings, or at least the feelings of those folks that you correspond with on Twitter. The tool has been updated to analyze Facebook's fan pages, timeline, news feed and comments.

One year ago this Spring I wrote a blog post titled "Stop What You Are Doing & Install This Plug-In: Rapportive" and for many of us who did, Gmail plug-in Rapportive is now an essential daily tool. The service displays social media profile and activity data for people you're corresponding with in the sidebar of your Gmail threads. It's awesome.

Today Rapportive got even better. No longer content to serve up information about people who have already emailed you, the service now runs ahead of your conversations and puts profile information in your sidebar as soon as you start composing an email. It might sound like a small thing, but it's really not. Check out the demo video below. You can get this feature now at rapportive.com/compose.

Late last month Google launched a Gmail plug-in that looked an awful lot like popular startup service Rapportive's sidebar CRM app - but with additional functionality from Google services like Calendar. What's a little startup to do? Rapportive's plan is apparently to move faster and adds more on top of what Google can do. That makes a must-have browser add-on even better.

Today Rapportive is announcing a big upgrade to its baked-in Twitter functionality. You can do so much Twitter stuff in the sidebar of your Gmail now! Check out the demo video below.

Once you've added x-ray vision to your email inbox, you'll never go back to life without it. The latest service to offer just that is Xobni, a high-profile startup that brought its Outlook plug-in out of Beta status a year ago next week. Today Xobni comes to Gmail and it looks really nice. The first 100 ReadWriteWeb readers who visit this link and enter the code XOBNI-RWW will be provided access to it. The company says iPhone and Android versions will open for testing within 90 days.

Xobni competes with Rapportive (my favorite to date) and Gist, which was recently acquired by Blackberry company RIM. Another service called eTacts (site now down) was recently acquired by Salesforce. Xobni was funded by Blackberry Partners a year ago, but remains independent. Check out the screenshot below to get a feel for how it looks, what it offers and how it's different.

2010 was a good year for Web startups. Deal flow, particularly at early stages, was active, and even though valuations were high, investor dollars were seemingly at the ready. Of the companies that made headlines and that led some of the major tech trends of the year, many were startups: Zynga (social gaming), Groupon (group buying), Foursquare (location-based networks), Tumblr (micro-blogging), and GetGlue (semantic Web), to name a few.

In pulling together our list of the Top 10 Startups of 2010 for ReadWriteWeb's "Best of" series, we've decided to look beyond some of those big names and "established" startups (the term gets applied so broadly). Rather than lumping together new companies no matter their age or size, no matter whether they have an acquisition offer by Google or have a Hollywood biopic about their founder, we've decided to restrict our list to those startups who were founded or who launched in 2010.

Etacts, an email add-on that layers social network profiles, conversation history and other relationship management information on top of your email conversations, announced abruptly this morning that it is shutting down its service, deleting all customer data at the end of next month and has "decided to pursue other opportunities."

Having raised more than a half million dollars from some of the hottest investors in Silicon Valley just over six months ago, it's unlikely the Etacts team has decided to go do something unrelated. It is most likely the company has been acquired by a larger firm that does heavy business in email. The Inbox 2.0 market has long been expected to heat up and indeed it has. Etacts competitor Rapportive also recently drew big name funding, Gist is rumored to be in acquisition talks with RIM and now Etacts announces a mysterious shut-down. Update: See our subsequent coverage, it appears to be Salesforce that has acquired Etacts.

The Internet, Congress and possibly your Mom are all freaking out this week about a Wall St. Journal article challenging Facebook's passing of some limited User ID numbers to 3rd party companies, including advertisers. Many people consider it a privacy violation.

I challenged Facebook as vehemently as anyone on the Internet a year ago when the company switched its user privacy setting from default private to default public, but this latest critique really misses the mark. Distribution of publicly available user data in bulk is wildly valuable - and not just for advertisers. Here are three examples of great things built by user data passed around the web.

Gist.com is a database of dynamic, information-rich user profiles that can be accessed via the Web or inside your email or other communication-management tool, or on your mobile device.

The database is populated with the people who have signed up for Gist's public beta and their contacts. There are 100 million profiles of people and companies behind Gist's wall, collected over about a year. Now, Gist wants users to "claim" their profiles by updating their own data (and potentially making some information public).