LinkedIn has taken further strides to embed itself in the enterprise social networking space with the introduction of a plugin for IBM’s Lotus Notes application. Jason Kincaid at TechCrunch reports:

“For users who spend much of their day ‘living’ in their Email client, the new plugin could be a welcome addition. Its primary purpose is to display information relevant to the people in your Emails, as well as providing a handy way to browse through some of LinkedIn’s most oft-used features (like your news feed and search). However, the plugin does not yet automatically look up the contacts mentioned in your Emails – you’ll still have to click on their names or use the pre-populated search to look them up (automatic lookup is planned for a future release).”

As Kincaid points out, Outlook users are already catered for through Xobni and LinkedIn’s own Outlook toolbar.

Elsewhere on the web:

Mike Butcher at TechCrunch UK reports on the explosion of Twitter usage in the UK, which has increased 10-fold over the last 12 months — and that’s not including stats around mobile usage. Meanwhile, Stan Schroder at Mashable has potentially bad news for Twitter app developers – Twitter’s limited the number of times any particular application can poll the service using the API. The SocialToo blog carries an indepth discussion of why the Twitter API rate limit will hamper development, saying:

“This is scary news as an entrepreneur and Twitter developer. Twitter has basically just limited how big any Twitter-based business can grow. This makes it worthless to build a business on top of Twitter now.”

The commentary in the SocialToo post is well worth a read for those checking the temperature of the developer community that’s sprung up around Twitter.

Finally, via Jeremiah Owyang, a bit of social networking humour in the form of the top 10 social networking annoyances. The list dates back to May 2008, and it’s fascinating to see how many of the annoyances picked up on by the authers has changed or even fallen away in the mere eight months since it was published — such as Ning shutting down the adult sites using its social community framework, thus addressing point #6 on this list.